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8efc0c15 | 1 | /* |
5260325f | 2 | * Author: Tatu Ylonen <ylo@cs.hut.fi> |
5260325f | 3 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
4 | * All rights reserved | |
5260325f | 5 | * This file contains functions for generic socket connection forwarding. |
6 | * There is also code for initiating connection forwarding for X11 connections, | |
7 | * arbitrary tcp/ip connections, and the authentication agent connection. | |
6ae2364d | 8 | * |
bcbf86ec | 9 | * As far as I am concerned, the code I have written for this software |
10 | * can be used freely for any purpose. Any derived versions of this | |
11 | * software must be clearly marked as such, and if the derived work is | |
12 | * incompatible with the protocol description in the RFC file, it must be | |
13 | * called by a name other than "ssh" or "Secure Shell". | |
14 | * | |
15 | * | |
7e7327a1 | 16 | * SSH2 support added by Markus Friedl. |
bcbf86ec | 17 | * Copyright (c) 1999,2000 Markus Friedl. All rights reserved. |
18 | * Copyright (c) 1999 Dug Song. All rights reserved. | |
19 | * Copyright (c) 1999 Theo de Raadt. All rights reserved. | |
20 | * | |
21 | * Redistribution and use in source and binary forms, with or without | |
22 | * modification, are permitted provided that the following conditions | |
23 | * are met: | |
24 | * 1. Redistributions of source code must retain the above copyright | |
25 | * notice, this list of conditions and the following disclaimer. | |
26 | * 2. Redistributions in binary form must reproduce the above copyright | |
27 | * notice, this list of conditions and the following disclaimer in the | |
28 | * documentation and/or other materials provided with the distribution. | |
29 | * | |
30 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | |
31 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |
32 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | |
33 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | |
34 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
35 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
36 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
37 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
38 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
39 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
5260325f | 40 | */ |
8efc0c15 | 41 | |
42 | #include "includes.h" | |
de273eef | 43 | RCSID("$OpenBSD: channels.c,v 1.70 2000/09/28 18:03:18 markus Exp $"); |
8efc0c15 | 44 | |
45 | #include "ssh.h" | |
46 | #include "packet.h" | |
47 | #include "xmalloc.h" | |
48 | #include "buffer.h" | |
8efc0c15 | 49 | #include "uidswap.h" |
6fa724bc | 50 | #include "readconf.h" |
8efc0c15 | 51 | #include "servconf.h" |
52 | ||
53 | #include "channels.h" | |
54 | #include "nchan.h" | |
55 | #include "compat.h" | |
56 | ||
7e7327a1 | 57 | #include "ssh2.h" |
4c8722d9 | 58 | |
59 | #include <openssl/rsa.h> | |
60 | #include <openssl/dsa.h> | |
61 | #include "key.h" | |
62 | #include "authfd.h" | |
7e7327a1 | 63 | |
8efc0c15 | 64 | /* Maximum number of fake X11 displays to try. */ |
65 | #define MAX_DISPLAYS 1000 | |
66 | ||
67 | /* Max len of agent socket */ | |
68 | #define MAX_SOCKET_NAME 100 | |
69 | ||
aa3378df | 70 | /* |
71 | * Pointer to an array containing all allocated channels. The array is | |
72 | * dynamically extended as needed. | |
73 | */ | |
8efc0c15 | 74 | static Channel *channels = NULL; |
75 | ||
aa3378df | 76 | /* |
77 | * Size of the channel array. All slots of the array must always be | |
78 | * initialized (at least the type field); unused slots are marked with type | |
79 | * SSH_CHANNEL_FREE. | |
80 | */ | |
8efc0c15 | 81 | static int channels_alloc = 0; |
82 | ||
aa3378df | 83 | /* |
84 | * Maximum file descriptor value used in any of the channels. This is | |
85 | * updated in channel_allocate. | |
86 | */ | |
8efc0c15 | 87 | static int channel_max_fd_value = 0; |
88 | ||
89 | /* Name and directory of socket for authentication agent forwarding. */ | |
90 | static char *channel_forwarded_auth_socket_name = NULL; | |
5260325f | 91 | static char *channel_forwarded_auth_socket_dir = NULL; |
8efc0c15 | 92 | |
93 | /* Saved X11 authentication protocol name. */ | |
94 | char *x11_saved_proto = NULL; | |
95 | ||
96 | /* Saved X11 authentication data. This is the real data. */ | |
97 | char *x11_saved_data = NULL; | |
98 | unsigned int x11_saved_data_len = 0; | |
99 | ||
aa3378df | 100 | /* |
101 | * Fake X11 authentication data. This is what the server will be sending us; | |
102 | * we should replace any occurrences of this by the real data. | |
103 | */ | |
8efc0c15 | 104 | char *x11_fake_data = NULL; |
105 | unsigned int x11_fake_data_len; | |
106 | ||
aa3378df | 107 | /* |
108 | * Data structure for storing which hosts are permitted for forward requests. | |
109 | * The local sides of any remote forwards are stored in this array to prevent | |
110 | * a corrupt remote server from accessing arbitrary TCP/IP ports on our local | |
111 | * network (which might be behind a firewall). | |
112 | */ | |
5260325f | 113 | typedef struct { |
7368a6c8 | 114 | char *host_to_connect; /* Connect to 'host'. */ |
115 | u_short port_to_connect; /* Connect to 'port'. */ | |
116 | u_short listen_port; /* Remote side should listen port number. */ | |
8efc0c15 | 117 | } ForwardPermission; |
118 | ||
119 | /* List of all permitted host/port pairs to connect. */ | |
120 | static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION]; | |
121 | /* Number of permitted host/port pairs in the array. */ | |
122 | static int num_permitted_opens = 0; | |
aa3378df | 123 | /* |
124 | * If this is true, all opens are permitted. This is the case on the server | |
125 | * on which we have to trust the client anyway, and the user could do | |
126 | * anything after logging in anyway. | |
127 | */ | |
8efc0c15 | 128 | static int all_opens_permitted = 0; |
129 | ||
130 | /* This is set to true if both sides support SSH_PROTOFLAG_HOST_IN_FWD_OPEN. */ | |
131 | static int have_hostname_in_open = 0; | |
132 | ||
133 | /* Sets specific protocol options. */ | |
134 | ||
6ae2364d | 135 | void |
5260325f | 136 | channel_set_options(int hostname_in_open) |
8efc0c15 | 137 | { |
5260325f | 138 | have_hostname_in_open = hostname_in_open; |
8efc0c15 | 139 | } |
140 | ||
aa3378df | 141 | /* |
142 | * Permits opening to any host/port in SSH_MSG_PORT_OPEN. This is usually | |
143 | * called by the server, because the user could connect to any port anyway, | |
144 | * and the server has no way to know but to trust the client anyway. | |
145 | */ | |
8efc0c15 | 146 | |
6ae2364d | 147 | void |
5260325f | 148 | channel_permit_all_opens() |
8efc0c15 | 149 | { |
5260325f | 150 | all_opens_permitted = 1; |
8efc0c15 | 151 | } |
152 | ||
7368a6c8 | 153 | /* lookup channel by id */ |
154 | ||
155 | Channel * | |
156 | channel_lookup(int id) | |
157 | { | |
158 | Channel *c; | |
3e98362e | 159 | if (id < 0 || id > channels_alloc) { |
7368a6c8 | 160 | log("channel_lookup: %d: bad id", id); |
161 | return NULL; | |
162 | } | |
163 | c = &channels[id]; | |
164 | if (c->type == SSH_CHANNEL_FREE) { | |
165 | log("channel_lookup: %d: bad id: channel free", id); | |
166 | return NULL; | |
167 | } | |
168 | return c; | |
169 | } | |
170 | ||
aa3378df | 171 | /* |
1d1ffb87 | 172 | * Register filedescriptors for a channel, used when allocating a channel or |
0fbe8c74 | 173 | * when the channel consumer/producer is ready, e.g. shell exec'd |
aa3378df | 174 | */ |
8efc0c15 | 175 | |
0fbe8c74 | 176 | void |
177 | channel_register_fds(Channel *c, int rfd, int wfd, int efd, int extusage) | |
8efc0c15 | 178 | { |
5260325f | 179 | /* Update the maximum file descriptor value. */ |
7368a6c8 | 180 | if (rfd > channel_max_fd_value) |
181 | channel_max_fd_value = rfd; | |
182 | if (wfd > channel_max_fd_value) | |
183 | channel_max_fd_value = wfd; | |
184 | if (efd > channel_max_fd_value) | |
185 | channel_max_fd_value = efd; | |
aa3378df | 186 | /* XXX set close-on-exec -markus */ |
1d1ffb87 | 187 | |
0fbe8c74 | 188 | c->rfd = rfd; |
189 | c->wfd = wfd; | |
190 | c->sock = (rfd == wfd) ? rfd : -1; | |
191 | c->efd = efd; | |
192 | c->extended_usage = extusage; | |
1d1ffb87 | 193 | if (rfd != -1) |
194 | set_nonblock(rfd); | |
195 | if (wfd != -1) | |
196 | set_nonblock(wfd); | |
197 | if (efd != -1) | |
198 | set_nonblock(efd); | |
0fbe8c74 | 199 | } |
200 | ||
201 | /* | |
202 | * Allocate a new channel object and set its type and socket. This will cause | |
203 | * remote_name to be freed. | |
204 | */ | |
205 | ||
206 | int | |
207 | channel_new(char *ctype, int type, int rfd, int wfd, int efd, | |
208 | int window, int maxpack, int extusage, char *remote_name) | |
209 | { | |
210 | int i, found; | |
211 | Channel *c; | |
5260325f | 212 | |
213 | /* Do initial allocation if this is the first call. */ | |
214 | if (channels_alloc == 0) { | |
7e7327a1 | 215 | chan_init(); |
5260325f | 216 | channels_alloc = 10; |
217 | channels = xmalloc(channels_alloc * sizeof(Channel)); | |
218 | for (i = 0; i < channels_alloc; i++) | |
219 | channels[i].type = SSH_CHANNEL_FREE; | |
aa3378df | 220 | /* |
221 | * Kludge: arrange a call to channel_stop_listening if we | |
222 | * terminate with fatal(). | |
223 | */ | |
5260325f | 224 | fatal_add_cleanup((void (*) (void *)) channel_stop_listening, NULL); |
225 | } | |
226 | /* Try to find a free slot where to put the new channel. */ | |
227 | for (found = -1, i = 0; i < channels_alloc; i++) | |
228 | if (channels[i].type == SSH_CHANNEL_FREE) { | |
229 | /* Found a free slot. */ | |
230 | found = i; | |
231 | break; | |
232 | } | |
233 | if (found == -1) { | |
aa3378df | 234 | /* There are no free slots. Take last+1 slot and expand the array. */ |
5260325f | 235 | found = channels_alloc; |
236 | channels_alloc += 10; | |
de273eef | 237 | debug2("channel: expanding %d", channels_alloc); |
5260325f | 238 | channels = xrealloc(channels, channels_alloc * sizeof(Channel)); |
239 | for (i = found; i < channels_alloc; i++) | |
240 | channels[i].type = SSH_CHANNEL_FREE; | |
241 | } | |
242 | /* Initialize and return new channel number. */ | |
243 | c = &channels[found]; | |
244 | buffer_init(&c->input); | |
245 | buffer_init(&c->output); | |
7368a6c8 | 246 | buffer_init(&c->extended); |
5260325f | 247 | chan_init_iostates(c); |
0fbe8c74 | 248 | channel_register_fds(c, rfd, wfd, efd, extusage); |
5260325f | 249 | c->self = found; |
250 | c->type = type; | |
7368a6c8 | 251 | c->ctype = ctype; |
0b242b12 | 252 | c->local_window = window; |
253 | c->local_window_max = window; | |
254 | c->local_consumed = 0; | |
255 | c->local_maxpacket = maxpack; | |
5260325f | 256 | c->remote_id = -1; |
257 | c->remote_name = remote_name; | |
7368a6c8 | 258 | c->remote_window = 0; |
259 | c->remote_maxpacket = 0; | |
260 | c->cb_fn = NULL; | |
261 | c->cb_arg = NULL; | |
262 | c->cb_event = 0; | |
263 | c->dettach_user = NULL; | |
2e73a022 | 264 | c->input_filter = NULL; |
5260325f | 265 | debug("channel %d: new [%s]", found, remote_name); |
266 | return found; | |
8efc0c15 | 267 | } |
0fbe8c74 | 268 | /* old interface XXX */ |
6ae2364d | 269 | int |
7368a6c8 | 270 | channel_allocate(int type, int sock, char *remote_name) |
271 | { | |
272 | return channel_new("", type, sock, sock, -1, 0, 0, 0, remote_name); | |
273 | } | |
8efc0c15 | 274 | |
0fbe8c74 | 275 | |
276 | /* Close all channel fd/socket. */ | |
277 | ||
278 | void | |
279 | channel_close_fds(Channel *c) | |
280 | { | |
281 | if (c->sock != -1) { | |
282 | close(c->sock); | |
283 | c->sock = -1; | |
284 | } | |
285 | if (c->rfd != -1) { | |
286 | close(c->rfd); | |
287 | c->rfd = -1; | |
288 | } | |
289 | if (c->wfd != -1) { | |
290 | close(c->wfd); | |
291 | c->wfd = -1; | |
292 | } | |
293 | if (c->efd != -1) { | |
294 | close(c->efd); | |
295 | c->efd = -1; | |
296 | } | |
297 | } | |
298 | ||
299 | /* Free the channel and close its fd/socket. */ | |
8efc0c15 | 300 | |
6ae2364d | 301 | void |
7368a6c8 | 302 | channel_free(int id) |
8efc0c15 | 303 | { |
7368a6c8 | 304 | Channel *c = channel_lookup(id); |
305 | if (c == NULL) | |
306 | packet_disconnect("channel free: bad local channel %d", id); | |
307 | debug("channel_free: channel %d: status: %s", id, channel_open_message()); | |
7e7327a1 | 308 | if (c->dettach_user != NULL) { |
309 | debug("channel_free: channel %d: dettaching channel user", id); | |
310 | c->dettach_user(c->self, NULL); | |
311 | } | |
0fbe8c74 | 312 | if (c->sock != -1) |
7368a6c8 | 313 | shutdown(c->sock, SHUT_RDWR); |
0fbe8c74 | 314 | channel_close_fds(c); |
7368a6c8 | 315 | buffer_free(&c->input); |
316 | buffer_free(&c->output); | |
317 | buffer_free(&c->extended); | |
318 | c->type = SSH_CHANNEL_FREE; | |
319 | if (c->remote_name) { | |
320 | xfree(c->remote_name); | |
321 | c->remote_name = NULL; | |
5260325f | 322 | } |
8efc0c15 | 323 | } |
324 | ||
aa3378df | 325 | /* |
7368a6c8 | 326 | * 'channel_pre*' are called just before select() to add any bits relevant to |
327 | * channels in the select bitmasks. | |
aa3378df | 328 | */ |
7368a6c8 | 329 | /* |
330 | * 'channel_post*': perform any appropriate operations for channels which | |
331 | * have events pending. | |
332 | */ | |
333 | typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset); | |
334 | chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE]; | |
335 | chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE]; | |
8efc0c15 | 336 | |
7368a6c8 | 337 | void |
338 | channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset) | |
8efc0c15 | 339 | { |
7368a6c8 | 340 | FD_SET(c->sock, readset); |
341 | } | |
5260325f | 342 | |
7368a6c8 | 343 | void |
344 | channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset) | |
345 | { | |
346 | if (buffer_len(&c->input) < packet_get_maxsize()) | |
347 | FD_SET(c->sock, readset); | |
348 | if (buffer_len(&c->output) > 0) | |
349 | FD_SET(c->sock, writeset); | |
350 | } | |
5260325f | 351 | |
7368a6c8 | 352 | void |
353 | channel_pre_open_15(Channel *c, fd_set * readset, fd_set * writeset) | |
354 | { | |
355 | /* test whether sockets are 'alive' for read/write */ | |
356 | if (c->istate == CHAN_INPUT_OPEN) | |
357 | if (buffer_len(&c->input) < packet_get_maxsize()) | |
358 | FD_SET(c->sock, readset); | |
359 | if (c->ostate == CHAN_OUTPUT_OPEN || | |
360 | c->ostate == CHAN_OUTPUT_WAIT_DRAIN) { | |
361 | if (buffer_len(&c->output) > 0) { | |
362 | FD_SET(c->sock, writeset); | |
363 | } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) { | |
364 | chan_obuf_empty(c); | |
365 | } | |
366 | } | |
367 | } | |
5260325f | 368 | |
7e7327a1 | 369 | void |
370 | channel_pre_open_20(Channel *c, fd_set * readset, fd_set * writeset) | |
371 | { | |
372 | if (c->istate == CHAN_INPUT_OPEN && | |
373 | c->remote_window > 0 && | |
374 | buffer_len(&c->input) < c->remote_window) | |
375 | FD_SET(c->rfd, readset); | |
376 | if (c->ostate == CHAN_OUTPUT_OPEN || | |
377 | c->ostate == CHAN_OUTPUT_WAIT_DRAIN) { | |
378 | if (buffer_len(&c->output) > 0) { | |
379 | FD_SET(c->wfd, writeset); | |
380 | } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) { | |
381 | chan_obuf_empty(c); | |
382 | } | |
383 | } | |
384 | /** XXX check close conditions, too */ | |
385 | if (c->efd != -1) { | |
386 | if (c->extended_usage == CHAN_EXTENDED_WRITE && | |
387 | buffer_len(&c->extended) > 0) | |
388 | FD_SET(c->efd, writeset); | |
389 | else if (c->extended_usage == CHAN_EXTENDED_READ && | |
390 | buffer_len(&c->extended) < c->remote_window) | |
391 | FD_SET(c->efd, readset); | |
392 | } | |
393 | } | |
394 | ||
7368a6c8 | 395 | void |
396 | channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset) | |
397 | { | |
398 | if (buffer_len(&c->input) == 0) { | |
399 | packet_start(SSH_MSG_CHANNEL_CLOSE); | |
400 | packet_put_int(c->remote_id); | |
401 | packet_send(); | |
402 | c->type = SSH_CHANNEL_CLOSED; | |
403 | debug("Closing channel %d after input drain.", c->self); | |
404 | } | |
405 | } | |
5260325f | 406 | |
7368a6c8 | 407 | void |
408 | channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset) | |
409 | { | |
410 | if (buffer_len(&c->output) == 0) | |
411 | channel_free(c->self); | |
6ae2364d | 412 | else |
7368a6c8 | 413 | FD_SET(c->sock, writeset); |
414 | } | |
5260325f | 415 | |
7368a6c8 | 416 | /* |
417 | * This is a special state for X11 authentication spoofing. An opened X11 | |
418 | * connection (when authentication spoofing is being done) remains in this | |
419 | * state until the first packet has been completely read. The authentication | |
420 | * data in that packet is then substituted by the real data if it matches the | |
421 | * fake data, and the channel is put into normal mode. | |
0b242b12 | 422 | * XXX All this happens at the client side. |
7368a6c8 | 423 | */ |
424 | int | |
425 | x11_open_helper(Channel *c) | |
426 | { | |
427 | unsigned char *ucp; | |
428 | unsigned int proto_len, data_len; | |
5260325f | 429 | |
7368a6c8 | 430 | /* Check if the fixed size part of the packet is in buffer. */ |
431 | if (buffer_len(&c->output) < 12) | |
432 | return 0; | |
433 | ||
434 | /* Parse the lengths of variable-length fields. */ | |
435 | ucp = (unsigned char *) buffer_ptr(&c->output); | |
436 | if (ucp[0] == 0x42) { /* Byte order MSB first. */ | |
437 | proto_len = 256 * ucp[6] + ucp[7]; | |
438 | data_len = 256 * ucp[8] + ucp[9]; | |
439 | } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */ | |
440 | proto_len = ucp[6] + 256 * ucp[7]; | |
441 | data_len = ucp[8] + 256 * ucp[9]; | |
442 | } else { | |
443 | debug("Initial X11 packet contains bad byte order byte: 0x%x", | |
444 | ucp[0]); | |
445 | return -1; | |
446 | } | |
5260325f | 447 | |
7368a6c8 | 448 | /* Check if the whole packet is in buffer. */ |
449 | if (buffer_len(&c->output) < | |
450 | 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3)) | |
451 | return 0; | |
5260325f | 452 | |
7368a6c8 | 453 | /* Check if authentication protocol matches. */ |
454 | if (proto_len != strlen(x11_saved_proto) || | |
455 | memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) { | |
456 | debug("X11 connection uses different authentication protocol."); | |
457 | return -1; | |
458 | } | |
459 | /* Check if authentication data matches our fake data. */ | |
460 | if (data_len != x11_fake_data_len || | |
461 | memcmp(ucp + 12 + ((proto_len + 3) & ~3), | |
462 | x11_fake_data, x11_fake_data_len) != 0) { | |
463 | debug("X11 auth data does not match fake data."); | |
464 | return -1; | |
465 | } | |
466 | /* Check fake data length */ | |
467 | if (x11_fake_data_len != x11_saved_data_len) { | |
468 | error("X11 fake_data_len %d != saved_data_len %d", | |
469 | x11_fake_data_len, x11_saved_data_len); | |
470 | return -1; | |
471 | } | |
472 | /* | |
473 | * Received authentication protocol and data match | |
474 | * our fake data. Substitute the fake data with real | |
475 | * data. | |
476 | */ | |
477 | memcpy(ucp + 12 + ((proto_len + 3) & ~3), | |
478 | x11_saved_data, x11_saved_data_len); | |
479 | return 1; | |
480 | } | |
5260325f | 481 | |
7368a6c8 | 482 | void |
483 | channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset) | |
484 | { | |
485 | int ret = x11_open_helper(c); | |
486 | if (ret == 1) { | |
487 | /* Start normal processing for the channel. */ | |
488 | c->type = SSH_CHANNEL_OPEN; | |
a8be9f80 | 489 | channel_pre_open_13(c, readset, writeset); |
7368a6c8 | 490 | } else if (ret == -1) { |
491 | /* | |
492 | * We have received an X11 connection that has bad | |
493 | * authentication information. | |
494 | */ | |
495 | log("X11 connection rejected because of wrong authentication.\r\n"); | |
496 | buffer_clear(&c->input); | |
497 | buffer_clear(&c->output); | |
498 | close(c->sock); | |
499 | c->sock = -1; | |
500 | c->type = SSH_CHANNEL_CLOSED; | |
501 | packet_start(SSH_MSG_CHANNEL_CLOSE); | |
502 | packet_put_int(c->remote_id); | |
503 | packet_send(); | |
504 | } | |
505 | } | |
5260325f | 506 | |
7368a6c8 | 507 | void |
0b242b12 | 508 | channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset) |
7368a6c8 | 509 | { |
510 | int ret = x11_open_helper(c); | |
511 | if (ret == 1) { | |
512 | c->type = SSH_CHANNEL_OPEN; | |
d0c832f3 | 513 | if (compat20) |
514 | channel_pre_open_20(c, readset, writeset); | |
515 | else | |
516 | channel_pre_open_15(c, readset, writeset); | |
7368a6c8 | 517 | } else if (ret == -1) { |
518 | debug("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate); | |
0b242b12 | 519 | chan_read_failed(c); /** force close? */ |
7368a6c8 | 520 | chan_write_failed(c); |
521 | debug("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate); | |
522 | } | |
523 | } | |
5260325f | 524 | |
7368a6c8 | 525 | /* This is our fake X11 server socket. */ |
526 | void | |
527 | channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset) | |
528 | { | |
529 | struct sockaddr addr; | |
530 | int newsock, newch; | |
531 | socklen_t addrlen; | |
532 | char buf[16384], *remote_hostname; | |
0b242b12 | 533 | int remote_port; |
7368a6c8 | 534 | |
535 | if (FD_ISSET(c->sock, readset)) { | |
536 | debug("X11 connection requested."); | |
537 | addrlen = sizeof(addr); | |
538 | newsock = accept(c->sock, &addr, &addrlen); | |
539 | if (newsock < 0) { | |
540 | error("accept: %.100s", strerror(errno)); | |
541 | return; | |
5260325f | 542 | } |
7368a6c8 | 543 | remote_hostname = get_remote_hostname(newsock); |
0b242b12 | 544 | remote_port = get_peer_port(newsock); |
7368a6c8 | 545 | snprintf(buf, sizeof buf, "X11 connection from %.200s port %d", |
0b242b12 | 546 | remote_hostname, remote_port); |
547 | ||
548 | newch = channel_new("x11", | |
549 | SSH_CHANNEL_OPENING, newsock, newsock, -1, | |
550 | c->local_window_max, c->local_maxpacket, | |
551 | 0, xstrdup(buf)); | |
552 | if (compat20) { | |
553 | packet_start(SSH2_MSG_CHANNEL_OPEN); | |
554 | packet_put_cstring("x11"); | |
555 | packet_put_int(newch); | |
556 | packet_put_int(c->local_window_max); | |
557 | packet_put_int(c->local_maxpacket); | |
558 | /* originator host and port */ | |
559 | packet_put_cstring(remote_hostname); | |
d0c832f3 | 560 | if (datafellows & SSH_BUG_X11FWD) { |
561 | debug("ssh2 x11 bug compat mode"); | |
562 | } else { | |
563 | packet_put_int(remote_port); | |
564 | } | |
0b242b12 | 565 | packet_send(); |
566 | } else { | |
567 | packet_start(SSH_SMSG_X11_OPEN); | |
568 | packet_put_int(newch); | |
569 | if (have_hostname_in_open) | |
570 | packet_put_string(buf, strlen(buf)); | |
571 | packet_send(); | |
572 | } | |
7368a6c8 | 573 | xfree(remote_hostname); |
8efc0c15 | 574 | } |
8efc0c15 | 575 | } |
576 | ||
aa3378df | 577 | /* |
7368a6c8 | 578 | * This socket is listening for connections to a forwarded TCP/IP port. |
aa3378df | 579 | */ |
7368a6c8 | 580 | void |
581 | channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset) | |
582 | { | |
583 | struct sockaddr addr; | |
584 | int newsock, newch; | |
585 | socklen_t addrlen; | |
586 | char buf[1024], *remote_hostname; | |
587 | int remote_port; | |
588 | ||
589 | if (FD_ISSET(c->sock, readset)) { | |
590 | debug("Connection to port %d forwarding " | |
591 | "to %.100s port %d requested.", | |
592 | c->listening_port, c->path, c->host_port); | |
593 | addrlen = sizeof(addr); | |
594 | newsock = accept(c->sock, &addr, &addrlen); | |
595 | if (newsock < 0) { | |
596 | error("accept: %.100s", strerror(errno)); | |
597 | return; | |
598 | } | |
599 | remote_hostname = get_remote_hostname(newsock); | |
600 | remote_port = get_peer_port(newsock); | |
601 | snprintf(buf, sizeof buf, | |
602 | "listen port %d for %.100s port %d, " | |
603 | "connect from %.200s port %d", | |
604 | c->listening_port, c->path, c->host_port, | |
605 | remote_hostname, remote_port); | |
606 | newch = channel_new("direct-tcpip", | |
607 | SSH_CHANNEL_OPENING, newsock, newsock, -1, | |
608 | c->local_window_max, c->local_maxpacket, | |
609 | 0, xstrdup(buf)); | |
7e7327a1 | 610 | if (compat20) { |
611 | packet_start(SSH2_MSG_CHANNEL_OPEN); | |
612 | packet_put_cstring("direct-tcpip"); | |
613 | packet_put_int(newch); | |
614 | packet_put_int(c->local_window_max); | |
615 | packet_put_int(c->local_maxpacket); | |
6ae2364d | 616 | /* target host and port */ |
7e7327a1 | 617 | packet_put_string(c->path, strlen(c->path)); |
618 | packet_put_int(c->host_port); | |
6ae2364d | 619 | /* originator host and port */ |
7e7327a1 | 620 | packet_put_cstring(remote_hostname); |
621 | packet_put_int(remote_port); | |
622 | packet_send(); | |
623 | } else { | |
624 | packet_start(SSH_MSG_PORT_OPEN); | |
625 | packet_put_int(newch); | |
626 | packet_put_string(c->path, strlen(c->path)); | |
627 | packet_put_int(c->host_port); | |
628 | if (have_hostname_in_open) { | |
629 | packet_put_string(buf, strlen(buf)); | |
630 | } | |
631 | packet_send(); | |
7368a6c8 | 632 | } |
7368a6c8 | 633 | xfree(remote_hostname); |
634 | } | |
635 | } | |
8efc0c15 | 636 | |
7368a6c8 | 637 | /* |
638 | * This is the authentication agent socket listening for connections from | |
639 | * clients. | |
640 | */ | |
641 | void | |
642 | channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset) | |
8efc0c15 | 643 | { |
5260325f | 644 | struct sockaddr addr; |
7368a6c8 | 645 | int newsock, newch; |
48e671d5 | 646 | socklen_t addrlen; |
5260325f | 647 | |
7368a6c8 | 648 | if (FD_ISSET(c->sock, readset)) { |
649 | addrlen = sizeof(addr); | |
650 | newsock = accept(c->sock, &addr, &addrlen); | |
651 | if (newsock < 0) { | |
652 | error("accept from auth socket: %.100s", strerror(errno)); | |
653 | return; | |
654 | } | |
655 | newch = channel_allocate(SSH_CHANNEL_OPENING, newsock, | |
656 | xstrdup("accepted auth socket")); | |
657 | packet_start(SSH_SMSG_AGENT_OPEN); | |
658 | packet_put_int(newch); | |
659 | packet_send(); | |
660 | } | |
661 | } | |
5260325f | 662 | |
7368a6c8 | 663 | int |
664 | channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset) | |
665 | { | |
666 | char buf[16*1024]; | |
667 | int len; | |
668 | ||
669 | if (c->rfd != -1 && | |
670 | FD_ISSET(c->rfd, readset)) { | |
671 | len = read(c->rfd, buf, sizeof(buf)); | |
0fbe8c74 | 672 | if (len < 0 && (errno == EINTR || errno == EAGAIN)) |
673 | return 1; | |
7368a6c8 | 674 | if (len <= 0) { |
0b242b12 | 675 | debug("channel %d: read<=0 rfd %d len %d", |
7368a6c8 | 676 | c->self, c->rfd, len); |
677 | if (compat13) { | |
678 | buffer_consume(&c->output, buffer_len(&c->output)); | |
679 | c->type = SSH_CHANNEL_INPUT_DRAINING; | |
680 | debug("Channel %d status set to input draining.", c->self); | |
681 | } else { | |
682 | chan_read_failed(c); | |
5260325f | 683 | } |
7368a6c8 | 684 | return -1; |
685 | } | |
2e73a022 | 686 | if(c->input_filter != NULL) { |
687 | if (c->input_filter(c, buf, len) == -1) { | |
688 | debug("filter stops channel %d", c->self); | |
689 | chan_read_failed(c); | |
690 | } | |
691 | } else { | |
692 | buffer_append(&c->input, buf, len); | |
693 | } | |
7368a6c8 | 694 | } |
695 | return 1; | |
696 | } | |
697 | int | |
698 | channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset) | |
699 | { | |
700 | int len; | |
701 | ||
702 | /* Send buffered output data to the socket. */ | |
703 | if (c->wfd != -1 && | |
704 | FD_ISSET(c->wfd, writeset) && | |
705 | buffer_len(&c->output) > 0) { | |
706 | len = write(c->wfd, buffer_ptr(&c->output), | |
0fbe8c74 | 707 | buffer_len(&c->output)); |
708 | if (len < 0 && (errno == EINTR || errno == EAGAIN)) | |
709 | return 1; | |
7368a6c8 | 710 | if (len <= 0) { |
711 | if (compat13) { | |
712 | buffer_consume(&c->output, buffer_len(&c->output)); | |
713 | debug("Channel %d status set to input draining.", c->self); | |
714 | c->type = SSH_CHANNEL_INPUT_DRAINING; | |
715 | } else { | |
716 | chan_write_failed(c); | |
5260325f | 717 | } |
7368a6c8 | 718 | return -1; |
719 | } | |
720 | buffer_consume(&c->output, len); | |
7e7327a1 | 721 | if (compat20 && len > 0) { |
722 | c->local_consumed += len; | |
723 | } | |
724 | } | |
725 | return 1; | |
726 | } | |
727 | int | |
728 | channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset) | |
729 | { | |
730 | char buf[16*1024]; | |
731 | int len; | |
732 | ||
8ce64345 | 733 | /** XXX handle drain efd, too */ |
7e7327a1 | 734 | if (c->efd != -1) { |
735 | if (c->extended_usage == CHAN_EXTENDED_WRITE && | |
736 | FD_ISSET(c->efd, writeset) && | |
737 | buffer_len(&c->extended) > 0) { | |
738 | len = write(c->efd, buffer_ptr(&c->extended), | |
739 | buffer_len(&c->extended)); | |
de273eef | 740 | debug2("channel %d: written %d to efd %d", |
7e7327a1 | 741 | c->self, len, c->efd); |
742 | if (len > 0) { | |
743 | buffer_consume(&c->extended, len); | |
744 | c->local_consumed += len; | |
745 | } | |
746 | } else if (c->extended_usage == CHAN_EXTENDED_READ && | |
747 | FD_ISSET(c->efd, readset)) { | |
748 | len = read(c->efd, buf, sizeof(buf)); | |
de273eef | 749 | debug2("channel %d: read %d from efd %d", |
7e7327a1 | 750 | c->self, len, c->efd); |
8ce64345 | 751 | if (len == 0) { |
752 | debug("channel %d: closing efd %d", | |
753 | c->self, c->efd); | |
754 | close(c->efd); | |
755 | c->efd = -1; | |
756 | } else if (len > 0) | |
7e7327a1 | 757 | buffer_append(&c->extended, buf, len); |
758 | } | |
759 | } | |
760 | return 1; | |
761 | } | |
762 | int | |
763 | channel_check_window(Channel *c, fd_set * readset, fd_set * writeset) | |
764 | { | |
e78a59f5 | 765 | if (!(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) && |
7e7327a1 | 766 | c->local_window < c->local_window_max/2 && |
767 | c->local_consumed > 0) { | |
768 | packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST); | |
769 | packet_put_int(c->remote_id); | |
770 | packet_put_int(c->local_consumed); | |
771 | packet_send(); | |
de273eef | 772 | debug2("channel %d: window %d sent adjust %d", |
7e7327a1 | 773 | c->self, c->local_window, |
774 | c->local_consumed); | |
775 | c->local_window += c->local_consumed; | |
776 | c->local_consumed = 0; | |
7368a6c8 | 777 | } |
778 | return 1; | |
779 | } | |
5260325f | 780 | |
7368a6c8 | 781 | void |
782 | channel_post_open_1(Channel *c, fd_set * readset, fd_set * writeset) | |
783 | { | |
784 | channel_handle_rfd(c, readset, writeset); | |
785 | channel_handle_wfd(c, readset, writeset); | |
786 | } | |
aa3378df | 787 | |
7e7327a1 | 788 | void |
789 | channel_post_open_2(Channel *c, fd_set * readset, fd_set * writeset) | |
790 | { | |
791 | channel_handle_rfd(c, readset, writeset); | |
792 | channel_handle_wfd(c, readset, writeset); | |
793 | channel_handle_efd(c, readset, writeset); | |
794 | channel_check_window(c, readset, writeset); | |
795 | } | |
796 | ||
7368a6c8 | 797 | void |
798 | channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset) | |
799 | { | |
800 | int len; | |
801 | /* Send buffered output data to the socket. */ | |
802 | if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) { | |
803 | len = write(c->sock, buffer_ptr(&c->output), | |
804 | buffer_len(&c->output)); | |
805 | if (len <= 0) | |
806 | buffer_consume(&c->output, buffer_len(&c->output)); | |
807 | else | |
808 | buffer_consume(&c->output, len); | |
809 | } | |
810 | } | |
5260325f | 811 | |
7e7327a1 | 812 | void |
813 | channel_handler_init_20(void) | |
814 | { | |
815 | channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_20; | |
0b242b12 | 816 | channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open; |
7e7327a1 | 817 | channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener; |
0b242b12 | 818 | channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener; |
7e7327a1 | 819 | |
820 | channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_2; | |
821 | channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener; | |
0b242b12 | 822 | channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener; |
7e7327a1 | 823 | } |
824 | ||
7368a6c8 | 825 | void |
826 | channel_handler_init_13(void) | |
827 | { | |
828 | channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13; | |
829 | channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13; | |
830 | channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener; | |
831 | channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener; | |
832 | channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener; | |
833 | channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining; | |
834 | channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining; | |
835 | ||
836 | channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1; | |
837 | channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener; | |
838 | channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener; | |
839 | channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener; | |
840 | channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13; | |
841 | } | |
5260325f | 842 | |
7368a6c8 | 843 | void |
844 | channel_handler_init_15(void) | |
845 | { | |
846 | channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_15; | |
0b242b12 | 847 | channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open; |
7368a6c8 | 848 | channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener; |
849 | channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener; | |
850 | channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener; | |
851 | ||
852 | channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener; | |
853 | channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener; | |
854 | channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener; | |
855 | channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1; | |
856 | } | |
857 | ||
858 | void | |
859 | channel_handler_init(void) | |
860 | { | |
861 | int i; | |
862 | for(i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) { | |
863 | channel_pre[i] = NULL; | |
864 | channel_post[i] = NULL; | |
865 | } | |
7e7327a1 | 866 | if (compat20) |
867 | channel_handler_init_20(); | |
868 | else if (compat13) | |
7368a6c8 | 869 | channel_handler_init_13(); |
870 | else | |
871 | channel_handler_init_15(); | |
872 | } | |
873 | ||
6ae2364d | 874 | void |
7368a6c8 | 875 | channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset) |
876 | { | |
877 | static int did_init = 0; | |
878 | int i; | |
879 | Channel *c; | |
880 | ||
881 | if (!did_init) { | |
882 | channel_handler_init(); | |
883 | did_init = 1; | |
884 | } | |
885 | for (i = 0; i < channels_alloc; i++) { | |
886 | c = &channels[i]; | |
887 | if (c->type == SSH_CHANNEL_FREE) | |
5260325f | 888 | continue; |
7368a6c8 | 889 | if (ftab[c->type] == NULL) |
890 | continue; | |
891 | (*ftab[c->type])(c, readset, writeset); | |
7e7327a1 | 892 | chan_delete_if_full_closed(c); |
8efc0c15 | 893 | } |
8efc0c15 | 894 | } |
895 | ||
6ae2364d | 896 | void |
7368a6c8 | 897 | channel_prepare_select(fd_set * readset, fd_set * writeset) |
898 | { | |
899 | channel_handler(channel_pre, readset, writeset); | |
900 | } | |
901 | ||
6ae2364d | 902 | void |
7368a6c8 | 903 | channel_after_select(fd_set * readset, fd_set * writeset) |
904 | { | |
905 | channel_handler(channel_post, readset, writeset); | |
906 | } | |
907 | ||
8efc0c15 | 908 | /* If there is data to send to the connection, send some of it now. */ |
909 | ||
6ae2364d | 910 | void |
5260325f | 911 | channel_output_poll() |
8efc0c15 | 912 | { |
5260325f | 913 | int len, i; |
7368a6c8 | 914 | Channel *c; |
5260325f | 915 | |
916 | for (i = 0; i < channels_alloc; i++) { | |
7368a6c8 | 917 | c = &channels[i]; |
48e671d5 | 918 | |
aa3378df | 919 | /* We are only interested in channels that can have buffered incoming data. */ |
48e671d5 | 920 | if (compat13) { |
7368a6c8 | 921 | if (c->type != SSH_CHANNEL_OPEN && |
922 | c->type != SSH_CHANNEL_INPUT_DRAINING) | |
48e671d5 | 923 | continue; |
924 | } else { | |
7368a6c8 | 925 | if (c->type != SSH_CHANNEL_OPEN) |
48e671d5 | 926 | continue; |
7368a6c8 | 927 | if (c->istate != CHAN_INPUT_OPEN && |
928 | c->istate != CHAN_INPUT_WAIT_DRAIN) | |
48e671d5 | 929 | continue; |
930 | } | |
e78a59f5 | 931 | if (compat20 && |
932 | (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) { | |
7e7327a1 | 933 | debug("channel: %d: no data after CLOSE", c->self); |
934 | continue; | |
935 | } | |
5260325f | 936 | |
937 | /* Get the amount of buffered data for this channel. */ | |
7368a6c8 | 938 | len = buffer_len(&c->input); |
5260325f | 939 | if (len > 0) { |
aa3378df | 940 | /* Send some data for the other side over the secure connection. */ |
7e7327a1 | 941 | if (compat20) { |
942 | if (len > c->remote_window) | |
943 | len = c->remote_window; | |
944 | if (len > c->remote_maxpacket) | |
945 | len = c->remote_maxpacket; | |
5260325f | 946 | } else { |
7e7327a1 | 947 | if (packet_is_interactive()) { |
948 | if (len > 1024) | |
949 | len = 512; | |
950 | } else { | |
951 | /* Keep the packets at reasonable size. */ | |
952 | if (len > packet_get_maxsize()/2) | |
953 | len = packet_get_maxsize()/2; | |
954 | } | |
5260325f | 955 | } |
7368a6c8 | 956 | if (len > 0) { |
7e7327a1 | 957 | packet_start(compat20 ? |
958 | SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA); | |
7368a6c8 | 959 | packet_put_int(c->remote_id); |
960 | packet_put_string(buffer_ptr(&c->input), len); | |
961 | packet_send(); | |
962 | buffer_consume(&c->input, len); | |
963 | c->remote_window -= len; | |
7368a6c8 | 964 | } |
965 | } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) { | |
5260325f | 966 | if (compat13) |
967 | fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3"); | |
aa3378df | 968 | /* |
969 | * input-buffer is empty and read-socket shutdown: | |
970 | * tell peer, that we will not send more data: send IEOF | |
971 | */ | |
7368a6c8 | 972 | chan_ibuf_empty(c); |
5260325f | 973 | } |
7e7327a1 | 974 | /* Send extended data, i.e. stderr */ |
975 | if (compat20 && | |
976 | c->remote_window > 0 && | |
977 | (len = buffer_len(&c->extended)) > 0 && | |
978 | c->extended_usage == CHAN_EXTENDED_READ) { | |
979 | if (len > c->remote_window) | |
980 | len = c->remote_window; | |
981 | if (len > c->remote_maxpacket) | |
982 | len = c->remote_maxpacket; | |
983 | packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA); | |
984 | packet_put_int(c->remote_id); | |
985 | packet_put_int(SSH2_EXTENDED_DATA_STDERR); | |
986 | packet_put_string(buffer_ptr(&c->extended), len); | |
987 | packet_send(); | |
988 | buffer_consume(&c->extended, len); | |
989 | c->remote_window -= len; | |
990 | } | |
8efc0c15 | 991 | } |
8efc0c15 | 992 | } |
993 | ||
aa3378df | 994 | /* |
995 | * This is called when a packet of type CHANNEL_DATA has just been received. | |
996 | * The message type has already been consumed, but channel number and data is | |
997 | * still there. | |
998 | */ | |
8efc0c15 | 999 | |
6ae2364d | 1000 | void |
188adeb2 | 1001 | channel_input_data(int type, int plen, void *ctxt) |
8efc0c15 | 1002 | { |
48e671d5 | 1003 | int id; |
5260325f | 1004 | char *data; |
1005 | unsigned int data_len; | |
7368a6c8 | 1006 | Channel *c; |
5260325f | 1007 | |
1008 | /* Get the channel number and verify it. */ | |
48e671d5 | 1009 | id = packet_get_int(); |
7368a6c8 | 1010 | c = channel_lookup(id); |
1011 | if (c == NULL) | |
48e671d5 | 1012 | packet_disconnect("Received data for nonexistent channel %d.", id); |
5260325f | 1013 | |
1014 | /* Ignore any data for non-open channels (might happen on close) */ | |
7368a6c8 | 1015 | if (c->type != SSH_CHANNEL_OPEN && |
1016 | c->type != SSH_CHANNEL_X11_OPEN) | |
48e671d5 | 1017 | return; |
1018 | ||
1019 | /* same for protocol 1.5 if output end is no longer open */ | |
7368a6c8 | 1020 | if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) |
5260325f | 1021 | return; |
1022 | ||
1023 | /* Get the data. */ | |
1024 | data = packet_get_string(&data_len); | |
6ae2364d | 1025 | packet_done(); |
7368a6c8 | 1026 | |
7e7327a1 | 1027 | if (compat20){ |
1028 | if (data_len > c->local_maxpacket) { | |
1029 | log("channel %d: rcvd big packet %d, maxpack %d", | |
1030 | c->self, data_len, c->local_maxpacket); | |
1031 | } | |
1032 | if (data_len > c->local_window) { | |
1033 | log("channel %d: rcvd too much data %d, win %d", | |
1034 | c->self, data_len, c->local_window); | |
1035 | xfree(data); | |
1036 | return; | |
1037 | } | |
1038 | c->local_window -= data_len; | |
1039 | }else{ | |
1040 | packet_integrity_check(plen, 4 + 4 + data_len, type); | |
1041 | } | |
7368a6c8 | 1042 | buffer_append(&c->output, data, data_len); |
5260325f | 1043 | xfree(data); |
8efc0c15 | 1044 | } |
6ae2364d | 1045 | void |
188adeb2 | 1046 | channel_input_extended_data(int type, int plen, void *ctxt) |
7e7327a1 | 1047 | { |
1048 | int id; | |
1049 | int tcode; | |
1050 | char *data; | |
1051 | unsigned int data_len; | |
1052 | Channel *c; | |
1053 | ||
1054 | /* Get the channel number and verify it. */ | |
1055 | id = packet_get_int(); | |
1056 | c = channel_lookup(id); | |
1057 | ||
1058 | if (c == NULL) | |
1059 | packet_disconnect("Received extended_data for bad channel %d.", id); | |
1060 | if (c->type != SSH_CHANNEL_OPEN) { | |
1061 | log("channel %d: ext data for non open", id); | |
1062 | return; | |
1063 | } | |
1064 | tcode = packet_get_int(); | |
1065 | if (c->efd == -1 || | |
1066 | c->extended_usage != CHAN_EXTENDED_WRITE || | |
1067 | tcode != SSH2_EXTENDED_DATA_STDERR) { | |
1068 | log("channel %d: bad ext data", c->self); | |
1069 | return; | |
1070 | } | |
1071 | data = packet_get_string(&data_len); | |
6ae2364d | 1072 | packet_done(); |
7e7327a1 | 1073 | if (data_len > c->local_window) { |
1074 | log("channel %d: rcvd too much extended_data %d, win %d", | |
1075 | c->self, data_len, c->local_window); | |
1076 | xfree(data); | |
1077 | return; | |
1078 | } | |
de273eef | 1079 | debug2("channel %d: rcvd ext data %d", c->self, data_len); |
7e7327a1 | 1080 | c->local_window -= data_len; |
1081 | buffer_append(&c->extended, data, data_len); | |
1082 | xfree(data); | |
1083 | } | |
1084 | ||
8efc0c15 | 1085 | |
aa3378df | 1086 | /* |
1087 | * Returns true if no channel has too much buffered data, and false if one or | |
1088 | * more channel is overfull. | |
1089 | */ | |
8efc0c15 | 1090 | |
6ae2364d | 1091 | int |
5260325f | 1092 | channel_not_very_much_buffered_data() |
8efc0c15 | 1093 | { |
5260325f | 1094 | unsigned int i; |
7368a6c8 | 1095 | Channel *c; |
5260325f | 1096 | |
1097 | for (i = 0; i < channels_alloc; i++) { | |
7368a6c8 | 1098 | c = &channels[i]; |
1099 | if (c->type == SSH_CHANNEL_OPEN) { | |
7e7327a1 | 1100 | if (!compat20 && buffer_len(&c->input) > packet_get_maxsize()) { |
7368a6c8 | 1101 | debug("channel %d: big input buffer %d", |
1102 | c->self, buffer_len(&c->input)); | |
5260325f | 1103 | return 0; |
7368a6c8 | 1104 | } |
1105 | if (buffer_len(&c->output) > packet_get_maxsize()) { | |
1106 | debug("channel %d: big output buffer %d", | |
1107 | c->self, buffer_len(&c->output)); | |
5260325f | 1108 | return 0; |
7368a6c8 | 1109 | } |
5260325f | 1110 | } |
8efc0c15 | 1111 | } |
5260325f | 1112 | return 1; |
8efc0c15 | 1113 | } |
1114 | ||
6ae2364d | 1115 | void |
188adeb2 | 1116 | channel_input_ieof(int type, int plen, void *ctxt) |
7368a6c8 | 1117 | { |
1118 | int id; | |
1119 | Channel *c; | |
1120 | ||
1121 | packet_integrity_check(plen, 4, type); | |
1122 | ||
1123 | id = packet_get_int(); | |
1124 | c = channel_lookup(id); | |
1125 | if (c == NULL) | |
1126 | packet_disconnect("Received ieof for nonexistent channel %d.", id); | |
1127 | chan_rcvd_ieof(c); | |
1128 | } | |
8efc0c15 | 1129 | |
6ae2364d | 1130 | void |
188adeb2 | 1131 | channel_input_close(int type, int plen, void *ctxt) |
8efc0c15 | 1132 | { |
7368a6c8 | 1133 | int id; |
1134 | Channel *c; | |
5260325f | 1135 | |
7368a6c8 | 1136 | packet_integrity_check(plen, 4, type); |
1137 | ||
1138 | id = packet_get_int(); | |
1139 | c = channel_lookup(id); | |
1140 | if (c == NULL) | |
1141 | packet_disconnect("Received close for nonexistent channel %d.", id); | |
aa3378df | 1142 | |
1143 | /* | |
1144 | * Send a confirmation that we have closed the channel and no more | |
1145 | * data is coming for it. | |
1146 | */ | |
5260325f | 1147 | packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION); |
7368a6c8 | 1148 | packet_put_int(c->remote_id); |
5260325f | 1149 | packet_send(); |
1150 | ||
aa3378df | 1151 | /* |
1152 | * If the channel is in closed state, we have sent a close request, | |
1153 | * and the other side will eventually respond with a confirmation. | |
1154 | * Thus, we cannot free the channel here, because then there would be | |
1155 | * no-one to receive the confirmation. The channel gets freed when | |
1156 | * the confirmation arrives. | |
1157 | */ | |
7368a6c8 | 1158 | if (c->type != SSH_CHANNEL_CLOSED) { |
aa3378df | 1159 | /* |
1160 | * Not a closed channel - mark it as draining, which will | |
1161 | * cause it to be freed later. | |
1162 | */ | |
7368a6c8 | 1163 | buffer_consume(&c->input, buffer_len(&c->input)); |
1164 | c->type = SSH_CHANNEL_OUTPUT_DRAINING; | |
5260325f | 1165 | } |
8efc0c15 | 1166 | } |
1167 | ||
7368a6c8 | 1168 | /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */ |
6ae2364d | 1169 | void |
188adeb2 | 1170 | channel_input_oclose(int type, int plen, void *ctxt) |
8efc0c15 | 1171 | { |
7368a6c8 | 1172 | int id = packet_get_int(); |
1173 | Channel *c = channel_lookup(id); | |
1174 | packet_integrity_check(plen, 4, type); | |
1175 | if (c == NULL) | |
1176 | packet_disconnect("Received oclose for nonexistent channel %d.", id); | |
1177 | chan_rcvd_oclose(c); | |
8efc0c15 | 1178 | } |
1179 | ||
6ae2364d | 1180 | void |
188adeb2 | 1181 | channel_input_close_confirmation(int type, int plen, void *ctxt) |
7368a6c8 | 1182 | { |
1183 | int id = packet_get_int(); | |
1184 | Channel *c = channel_lookup(id); | |
1185 | ||
6ae2364d | 1186 | packet_done(); |
7368a6c8 | 1187 | if (c == NULL) |
1188 | packet_disconnect("Received close confirmation for " | |
1189 | "out-of-range channel %d.", id); | |
1190 | if (c->type != SSH_CHANNEL_CLOSED) | |
1191 | packet_disconnect("Received close confirmation for " | |
1192 | "non-closed channel %d (type %d).", id, c->type); | |
1193 | channel_free(c->self); | |
1194 | } | |
8efc0c15 | 1195 | |
6ae2364d | 1196 | void |
188adeb2 | 1197 | channel_input_open_confirmation(int type, int plen, void *ctxt) |
8efc0c15 | 1198 | { |
7368a6c8 | 1199 | int id, remote_id; |
1200 | Channel *c; | |
5260325f | 1201 | |
7e7327a1 | 1202 | if (!compat20) |
1203 | packet_integrity_check(plen, 4 + 4, type); | |
5260325f | 1204 | |
7368a6c8 | 1205 | id = packet_get_int(); |
1206 | c = channel_lookup(id); | |
5260325f | 1207 | |
7368a6c8 | 1208 | if (c==NULL || c->type != SSH_CHANNEL_OPENING) |
1209 | packet_disconnect("Received open confirmation for " | |
1210 | "non-opening channel %d.", id); | |
1211 | remote_id = packet_get_int(); | |
aa3378df | 1212 | /* Record the remote channel number and mark that the channel is now open. */ |
7368a6c8 | 1213 | c->remote_id = remote_id; |
1214 | c->type = SSH_CHANNEL_OPEN; | |
7e7327a1 | 1215 | |
1216 | if (compat20) { | |
1217 | c->remote_window = packet_get_int(); | |
1218 | c->remote_maxpacket = packet_get_int(); | |
6ae2364d | 1219 | packet_done(); |
7e7327a1 | 1220 | if (c->cb_fn != NULL && c->cb_event == type) { |
de273eef | 1221 | debug2("callback start"); |
7e7327a1 | 1222 | c->cb_fn(c->self, c->cb_arg); |
de273eef | 1223 | debug2("callback done"); |
7e7327a1 | 1224 | } |
1225 | debug("channel %d: open confirm rwindow %d rmax %d", c->self, | |
1226 | c->remote_window, c->remote_maxpacket); | |
1227 | } | |
8efc0c15 | 1228 | } |
1229 | ||
6ae2364d | 1230 | void |
188adeb2 | 1231 | channel_input_open_failure(int type, int plen, void *ctxt) |
8efc0c15 | 1232 | { |
7368a6c8 | 1233 | int id; |
1234 | Channel *c; | |
5260325f | 1235 | |
7e7327a1 | 1236 | if (!compat20) |
1237 | packet_integrity_check(plen, 4, type); | |
7368a6c8 | 1238 | |
1239 | id = packet_get_int(); | |
1240 | c = channel_lookup(id); | |
1241 | ||
1242 | if (c==NULL || c->type != SSH_CHANNEL_OPENING) | |
1243 | packet_disconnect("Received open failure for " | |
1244 | "non-opening channel %d.", id); | |
7e7327a1 | 1245 | if (compat20) { |
1246 | int reason = packet_get_int(); | |
1247 | char *msg = packet_get_string(NULL); | |
6ae2364d | 1248 | char *lang = packet_get_string(NULL); |
7e7327a1 | 1249 | log("channel_open_failure: %d: reason %d: %s", id, reason, msg); |
6ae2364d | 1250 | packet_done(); |
7e7327a1 | 1251 | xfree(msg); |
6ae2364d | 1252 | xfree(lang); |
7e7327a1 | 1253 | } |
5260325f | 1254 | /* Free the channel. This will also close the socket. */ |
7368a6c8 | 1255 | channel_free(id); |
8efc0c15 | 1256 | } |
1257 | ||
7e7327a1 | 1258 | void |
188adeb2 | 1259 | channel_input_channel_request(int type, int plen, void *ctxt) |
7e7327a1 | 1260 | { |
1261 | int id; | |
1262 | Channel *c; | |
1263 | ||
1264 | id = packet_get_int(); | |
1265 | c = channel_lookup(id); | |
1266 | ||
1267 | if (c == NULL || | |
1268 | (c->type != SSH_CHANNEL_OPEN && c->type != SSH_CHANNEL_LARVAL)) | |
1269 | packet_disconnect("Received request for " | |
1270 | "non-open channel %d.", id); | |
1271 | if (c->cb_fn != NULL && c->cb_event == type) { | |
de273eef | 1272 | debug2("callback start"); |
7e7327a1 | 1273 | c->cb_fn(c->self, c->cb_arg); |
de273eef | 1274 | debug2("callback done"); |
7e7327a1 | 1275 | } else { |
1276 | char *service = packet_get_string(NULL); | |
1277 | debug("channel: %d rcvd request for %s", c->self, service); | |
de273eef | 1278 | debug("cb_fn %p cb_event %d", c->cb_fn , c->cb_event); |
7e7327a1 | 1279 | xfree(service); |
1280 | } | |
1281 | } | |
1282 | ||
6ae2364d | 1283 | void |
188adeb2 | 1284 | channel_input_window_adjust(int type, int plen, void *ctxt) |
7e7327a1 | 1285 | { |
1286 | Channel *c; | |
1287 | int id, adjust; | |
1288 | ||
1289 | if (!compat20) | |
1290 | return; | |
1291 | ||
1292 | /* Get the channel number and verify it. */ | |
1293 | id = packet_get_int(); | |
1294 | c = channel_lookup(id); | |
1295 | ||
1296 | if (c == NULL || c->type != SSH_CHANNEL_OPEN) { | |
1297 | log("Received window adjust for " | |
1298 | "non-open channel %d.", id); | |
1299 | return; | |
1300 | } | |
1301 | adjust = packet_get_int(); | |
6ae2364d | 1302 | packet_done(); |
de273eef | 1303 | debug2("channel %d: rcvd adjust %d", id, adjust); |
7e7327a1 | 1304 | c->remote_window += adjust; |
1305 | } | |
1306 | ||
aa3378df | 1307 | /* |
1308 | * Stops listening for channels, and removes any unix domain sockets that we | |
1309 | * might have. | |
1310 | */ | |
8efc0c15 | 1311 | |
6ae2364d | 1312 | void |
5260325f | 1313 | channel_stop_listening() |
8efc0c15 | 1314 | { |
5260325f | 1315 | int i; |
1316 | for (i = 0; i < channels_alloc; i++) { | |
1317 | switch (channels[i].type) { | |
1318 | case SSH_CHANNEL_AUTH_SOCKET: | |
1319 | close(channels[i].sock); | |
77bb0bca | 1320 | unlink(channels[i].path); |
5260325f | 1321 | channel_free(i); |
1322 | break; | |
1323 | case SSH_CHANNEL_PORT_LISTENER: | |
1324 | case SSH_CHANNEL_X11_LISTENER: | |
1325 | close(channels[i].sock); | |
1326 | channel_free(i); | |
1327 | break; | |
1328 | default: | |
1329 | break; | |
1330 | } | |
8efc0c15 | 1331 | } |
8efc0c15 | 1332 | } |
1333 | ||
aa3378df | 1334 | /* |
0fbe8c74 | 1335 | * Closes the sockets/fds of all channels. This is used to close extra file |
aa3378df | 1336 | * descriptors after a fork. |
1337 | */ | |
8efc0c15 | 1338 | |
6ae2364d | 1339 | void |
5260325f | 1340 | channel_close_all() |
8efc0c15 | 1341 | { |
5260325f | 1342 | int i; |
0fbe8c74 | 1343 | for (i = 0; i < channels_alloc; i++) |
5260325f | 1344 | if (channels[i].type != SSH_CHANNEL_FREE) |
0fbe8c74 | 1345 | channel_close_fds(&channels[i]); |
8efc0c15 | 1346 | } |
1347 | ||
1348 | /* Returns the maximum file descriptor number used by the channels. */ | |
1349 | ||
6ae2364d | 1350 | int |
5260325f | 1351 | channel_max_fd() |
8efc0c15 | 1352 | { |
5260325f | 1353 | return channel_max_fd_value; |
8efc0c15 | 1354 | } |
1355 | ||
1356 | /* Returns true if any channel is still open. */ | |
1357 | ||
6ae2364d | 1358 | int |
5260325f | 1359 | channel_still_open() |
8efc0c15 | 1360 | { |
5260325f | 1361 | unsigned int i; |
1362 | for (i = 0; i < channels_alloc; i++) | |
1363 | switch (channels[i].type) { | |
1364 | case SSH_CHANNEL_FREE: | |
1365 | case SSH_CHANNEL_X11_LISTENER: | |
1366 | case SSH_CHANNEL_PORT_LISTENER: | |
1367 | case SSH_CHANNEL_CLOSED: | |
1368 | case SSH_CHANNEL_AUTH_SOCKET: | |
1369 | continue; | |
7e7327a1 | 1370 | case SSH_CHANNEL_LARVAL: |
1371 | if (!compat20) | |
1372 | fatal("cannot happen: SSH_CHANNEL_LARVAL"); | |
1373 | continue; | |
5260325f | 1374 | case SSH_CHANNEL_OPENING: |
1375 | case SSH_CHANNEL_OPEN: | |
1376 | case SSH_CHANNEL_X11_OPEN: | |
1377 | return 1; | |
1378 | case SSH_CHANNEL_INPUT_DRAINING: | |
1379 | case SSH_CHANNEL_OUTPUT_DRAINING: | |
1380 | if (!compat13) | |
1381 | fatal("cannot happen: OUT_DRAIN"); | |
1382 | return 1; | |
1383 | default: | |
1384 | fatal("channel_still_open: bad channel type %d", channels[i].type); | |
1385 | /* NOTREACHED */ | |
1386 | } | |
1387 | return 0; | |
8efc0c15 | 1388 | } |
1389 | ||
aa3378df | 1390 | /* |
1391 | * Returns a message describing the currently open forwarded connections, | |
1392 | * suitable for sending to the client. The message contains crlf pairs for | |
1393 | * newlines. | |
1394 | */ | |
8efc0c15 | 1395 | |
5260325f | 1396 | char * |
1397 | channel_open_message() | |
8efc0c15 | 1398 | { |
5260325f | 1399 | Buffer buffer; |
1400 | int i; | |
1401 | char buf[512], *cp; | |
1402 | ||
1403 | buffer_init(&buffer); | |
1404 | snprintf(buf, sizeof buf, "The following connections are open:\r\n"); | |
8efc0c15 | 1405 | buffer_append(&buffer, buf, strlen(buf)); |
5260325f | 1406 | for (i = 0; i < channels_alloc; i++) { |
1407 | Channel *c = &channels[i]; | |
1408 | switch (c->type) { | |
1409 | case SSH_CHANNEL_FREE: | |
1410 | case SSH_CHANNEL_X11_LISTENER: | |
1411 | case SSH_CHANNEL_PORT_LISTENER: | |
1412 | case SSH_CHANNEL_CLOSED: | |
1413 | case SSH_CHANNEL_AUTH_SOCKET: | |
1414 | continue; | |
7e7327a1 | 1415 | case SSH_CHANNEL_LARVAL: |
5260325f | 1416 | case SSH_CHANNEL_OPENING: |
1417 | case SSH_CHANNEL_OPEN: | |
1418 | case SSH_CHANNEL_X11_OPEN: | |
1419 | case SSH_CHANNEL_INPUT_DRAINING: | |
1420 | case SSH_CHANNEL_OUTPUT_DRAINING: | |
7368a6c8 | 1421 | snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n", |
48e671d5 | 1422 | c->self, c->remote_name, |
1423 | c->type, c->remote_id, | |
1424 | c->istate, buffer_len(&c->input), | |
7368a6c8 | 1425 | c->ostate, buffer_len(&c->output), |
1426 | c->rfd, c->wfd); | |
5260325f | 1427 | buffer_append(&buffer, buf, strlen(buf)); |
1428 | continue; | |
1429 | default: | |
7368a6c8 | 1430 | fatal("channel_open_message: bad channel type %d", c->type); |
5260325f | 1431 | /* NOTREACHED */ |
1432 | } | |
1433 | } | |
1434 | buffer_append(&buffer, "\0", 1); | |
1435 | cp = xstrdup(buffer_ptr(&buffer)); | |
1436 | buffer_free(&buffer); | |
1437 | return cp; | |
8efc0c15 | 1438 | } |
1439 | ||
aa3378df | 1440 | /* |
1441 | * Initiate forwarding of connections to local port "port" through the secure | |
1442 | * channel to host:port from remote side. | |
1443 | */ | |
8efc0c15 | 1444 | |
6ae2364d | 1445 | void |
57112b5a | 1446 | channel_request_local_forwarding(u_short port, const char *host, |
95f1eccc | 1447 | u_short host_port, int gateway_ports) |
8efc0c15 | 1448 | { |
48e671d5 | 1449 | int success, ch, sock, on = 1; |
1450 | struct addrinfo hints, *ai, *aitop; | |
1451 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; | |
aa3378df | 1452 | struct linger linger; |
5260325f | 1453 | |
1454 | if (strlen(host) > sizeof(channels[0].path) - 1) | |
1455 | packet_disconnect("Forward host name too long."); | |
1456 | ||
aa3378df | 1457 | /* |
48e671d5 | 1458 | * getaddrinfo returns a loopback address if the hostname is |
1459 | * set to NULL and hints.ai_flags is not AI_PASSIVE | |
aa3378df | 1460 | */ |
48e671d5 | 1461 | memset(&hints, 0, sizeof(hints)); |
1462 | hints.ai_family = IPv4or6; | |
1463 | hints.ai_flags = gateway_ports ? AI_PASSIVE : 0; | |
1464 | hints.ai_socktype = SOCK_STREAM; | |
1465 | snprintf(strport, sizeof strport, "%d", port); | |
1466 | if (getaddrinfo(NULL, strport, &hints, &aitop) != 0) | |
1467 | packet_disconnect("getaddrinfo: fatal error"); | |
1468 | ||
1469 | success = 0; | |
1470 | for (ai = aitop; ai; ai = ai->ai_next) { | |
1471 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
1472 | continue; | |
1473 | if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop), | |
1474 | strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) { | |
1475 | error("channel_request_local_forwarding: getnameinfo failed"); | |
1476 | continue; | |
1477 | } | |
1478 | /* Create a port to listen for the host. */ | |
1479 | sock = socket(ai->ai_family, SOCK_STREAM, 0); | |
1480 | if (sock < 0) { | |
1481 | /* this is no error since kernel may not support ipv6 */ | |
1482 | verbose("socket: %.100s", strerror(errno)); | |
1483 | continue; | |
1484 | } | |
1485 | /* | |
1486 | * Set socket options. We would like the socket to disappear | |
1487 | * as soon as it has been closed for whatever reason. | |
1488 | */ | |
1489 | setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on)); | |
1490 | linger.l_onoff = 1; | |
1491 | linger.l_linger = 5; | |
1492 | setsockopt(sock, SOL_SOCKET, SO_LINGER, (void *)&linger, sizeof(linger)); | |
1493 | debug("Local forwarding listening on %s port %s.", ntop, strport); | |
1494 | ||
1495 | /* Bind the socket to the address. */ | |
1496 | if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) { | |
1497 | /* address can be in use ipv6 address is already bound */ | |
16218745 | 1498 | if (!ai->ai_next) |
1499 | error("bind: %.100s", strerror(errno)); | |
1500 | else | |
1501 | verbose("bind: %.100s", strerror(errno)); | |
1502 | ||
48e671d5 | 1503 | close(sock); |
1504 | continue; | |
1505 | } | |
1506 | /* Start listening for connections on the socket. */ | |
1507 | if (listen(sock, 5) < 0) { | |
1508 | error("listen: %.100s", strerror(errno)); | |
1509 | close(sock); | |
1510 | continue; | |
1511 | } | |
1512 | /* Allocate a channel number for the socket. */ | |
7368a6c8 | 1513 | ch = channel_new( |
1514 | "port listener", SSH_CHANNEL_PORT_LISTENER, | |
1515 | sock, sock, -1, | |
0b242b12 | 1516 | CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, |
7368a6c8 | 1517 | 0, xstrdup("port listener")); |
48e671d5 | 1518 | strlcpy(channels[ch].path, host, sizeof(channels[ch].path)); |
1519 | channels[ch].host_port = host_port; | |
1520 | channels[ch].listening_port = port; | |
1521 | success = 1; | |
1522 | } | |
1523 | if (success == 0) | |
1524 | packet_disconnect("cannot listen port: %d", port); | |
1525 | freeaddrinfo(aitop); | |
5260325f | 1526 | } |
8efc0c15 | 1527 | |
aa3378df | 1528 | /* |
1529 | * Initiate forwarding of connections to port "port" on remote host through | |
1530 | * the secure channel to host:port from local side. | |
1531 | */ | |
8efc0c15 | 1532 | |
6ae2364d | 1533 | void |
7368a6c8 | 1534 | channel_request_remote_forwarding(u_short listen_port, const char *host_to_connect, |
1535 | u_short port_to_connect) | |
8efc0c15 | 1536 | { |
5260325f | 1537 | int payload_len; |
1538 | /* Record locally that connection to this host/port is permitted. */ | |
1539 | if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION) | |
1540 | fatal("channel_request_remote_forwarding: too many forwards"); | |
1541 | ||
7368a6c8 | 1542 | permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect); |
1543 | permitted_opens[num_permitted_opens].port_to_connect = port_to_connect; | |
1544 | permitted_opens[num_permitted_opens].listen_port = listen_port; | |
5260325f | 1545 | num_permitted_opens++; |
1546 | ||
1547 | /* Send the forward request to the remote side. */ | |
7e7327a1 | 1548 | if (compat20) { |
1549 | const char *address_to_bind = "0.0.0.0"; | |
1550 | packet_start(SSH2_MSG_GLOBAL_REQUEST); | |
1551 | packet_put_cstring("tcpip-forward"); | |
1552 | packet_put_char(0); /* boolean: want reply */ | |
1553 | packet_put_cstring(address_to_bind); | |
1554 | packet_put_int(listen_port); | |
1555 | } else { | |
1556 | packet_start(SSH_CMSG_PORT_FORWARD_REQUEST); | |
7e7327a1 | 1557 | packet_put_int(listen_port); |
d6f24e45 | 1558 | packet_put_cstring(host_to_connect); |
1559 | packet_put_int(port_to_connect); | |
7e7327a1 | 1560 | packet_send(); |
1561 | packet_write_wait(); | |
1562 | /* | |
1563 | * Wait for response from the remote side. It will send a disconnect | |
1564 | * message on failure, and we will never see it here. | |
1565 | */ | |
1566 | packet_read_expect(&payload_len, SSH_SMSG_SUCCESS); | |
1567 | } | |
8efc0c15 | 1568 | } |
1569 | ||
aa3378df | 1570 | /* |
1571 | * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates | |
1572 | * listening for the port, and sends back a success reply (or disconnect | |
1573 | * message if there was an error). This never returns if there was an error. | |
1574 | */ | |
8efc0c15 | 1575 | |
6ae2364d | 1576 | void |
1d1ffb87 | 1577 | channel_input_port_forward_request(int is_root, int gateway_ports) |
8efc0c15 | 1578 | { |
57112b5a | 1579 | u_short port, host_port; |
5260325f | 1580 | char *hostname; |
1581 | ||
1582 | /* Get arguments from the packet. */ | |
1583 | port = packet_get_int(); | |
1584 | hostname = packet_get_string(NULL); | |
1585 | host_port = packet_get_int(); | |
1586 | ||
3c62e7eb | 1587 | #ifndef HAVE_CYGWIN |
aa3378df | 1588 | /* |
1589 | * Check that an unprivileged user is not trying to forward a | |
1590 | * privileged port. | |
1591 | */ | |
5260325f | 1592 | if (port < IPPORT_RESERVED && !is_root) |
1593 | packet_disconnect("Requested forwarding of port %d but user is not root.", | |
1594 | port); | |
3c62e7eb | 1595 | #endif |
95f1eccc | 1596 | /* |
1597 | * Initiate forwarding, | |
95f1eccc | 1598 | */ |
1d1ffb87 | 1599 | channel_request_local_forwarding(port, hostname, host_port, gateway_ports); |
5260325f | 1600 | |
1601 | /* Free the argument string. */ | |
1602 | xfree(hostname); | |
8efc0c15 | 1603 | } |
1604 | ||
7368a6c8 | 1605 | /* XXX move to aux.c */ |
1606 | int | |
1607 | channel_connect_to(const char *host, u_short host_port) | |
8efc0c15 | 1608 | { |
48e671d5 | 1609 | struct addrinfo hints, *ai, *aitop; |
1610 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; | |
1611 | int gaierr; | |
7368a6c8 | 1612 | int sock = -1; |
48e671d5 | 1613 | |
1614 | memset(&hints, 0, sizeof(hints)); | |
1615 | hints.ai_family = IPv4or6; | |
1616 | hints.ai_socktype = SOCK_STREAM; | |
1617 | snprintf(strport, sizeof strport, "%d", host_port); | |
1618 | if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) { | |
1619 | error("%.100s: unknown host (%s)", host, gai_strerror(gaierr)); | |
7368a6c8 | 1620 | return -1; |
48e671d5 | 1621 | } |
48e671d5 | 1622 | for (ai = aitop; ai; ai = ai->ai_next) { |
1623 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
1624 | continue; | |
1625 | if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop), | |
1626 | strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) { | |
7368a6c8 | 1627 | error("channel_connect_to: getnameinfo failed"); |
48e671d5 | 1628 | continue; |
5260325f | 1629 | } |
48e671d5 | 1630 | /* Create the socket. */ |
1631 | sock = socket(ai->ai_family, SOCK_STREAM, 0); | |
1632 | if (sock < 0) { | |
1633 | error("socket: %.100s", strerror(errno)); | |
1634 | continue; | |
5260325f | 1635 | } |
48e671d5 | 1636 | /* Connect to the host/port. */ |
1637 | if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) { | |
1638 | error("connect %.100s port %s: %.100s", ntop, strport, | |
1639 | strerror(errno)); | |
1640 | close(sock); | |
1641 | continue; /* fail -- try next */ | |
1642 | } | |
1643 | break; /* success */ | |
5260325f | 1644 | |
5260325f | 1645 | } |
48e671d5 | 1646 | freeaddrinfo(aitop); |
48e671d5 | 1647 | if (!ai) { |
1648 | error("connect %.100s port %d: failed.", host, host_port); | |
7368a6c8 | 1649 | return -1; |
8efc0c15 | 1650 | } |
7368a6c8 | 1651 | /* success */ |
1652 | return sock; | |
1653 | } | |
48e671d5 | 1654 | |
7368a6c8 | 1655 | /* |
1656 | * This is called after receiving PORT_OPEN message. This attempts to | |
1657 | * connect to the given host:port, and sends back CHANNEL_OPEN_CONFIRMATION | |
1658 | * or CHANNEL_OPEN_FAILURE. | |
1659 | */ | |
5260325f | 1660 | |
6ae2364d | 1661 | void |
188adeb2 | 1662 | channel_input_port_open(int type, int plen, void *ctxt) |
7368a6c8 | 1663 | { |
1664 | u_short host_port; | |
1665 | char *host, *originator_string; | |
1666 | int remote_channel, sock = -1, newch, i, denied; | |
1667 | unsigned int host_len, originator_len; | |
5260325f | 1668 | |
7368a6c8 | 1669 | /* Get remote channel number. */ |
1670 | remote_channel = packet_get_int(); | |
5260325f | 1671 | |
7368a6c8 | 1672 | /* Get host name to connect to. */ |
1673 | host = packet_get_string(&host_len); | |
5260325f | 1674 | |
7368a6c8 | 1675 | /* Get port to connect to. */ |
1676 | host_port = packet_get_int(); | |
5260325f | 1677 | |
7368a6c8 | 1678 | /* Get remote originator name. */ |
1679 | if (have_hostname_in_open) { | |
1680 | originator_string = packet_get_string(&originator_len); | |
1681 | originator_len += 4; /* size of packet_int */ | |
1682 | } else { | |
1683 | originator_string = xstrdup("unknown (remote did not supply name)"); | |
1684 | originator_len = 0; /* no originator supplied */ | |
1685 | } | |
5260325f | 1686 | |
7368a6c8 | 1687 | packet_integrity_check(plen, |
1688 | 4 + 4 + host_len + 4 + originator_len, SSH_MSG_PORT_OPEN); | |
1689 | ||
1690 | /* Check if opening that port is permitted. */ | |
1691 | denied = 0; | |
1692 | if (!all_opens_permitted) { | |
1693 | /* Go trough all permitted ports. */ | |
1694 | for (i = 0; i < num_permitted_opens; i++) | |
1695 | if (permitted_opens[i].port_to_connect == host_port && | |
1696 | strcmp(permitted_opens[i].host_to_connect, host) == 0) | |
1697 | break; | |
1698 | ||
1699 | /* Check if we found the requested port among those permitted. */ | |
1700 | if (i >= num_permitted_opens) { | |
1701 | /* The port is not permitted. */ | |
1702 | log("Received request to connect to %.100s:%d, but the request was denied.", | |
1703 | host, host_port); | |
1704 | denied = 1; | |
1705 | } | |
1706 | } | |
1707 | sock = denied ? -1 : channel_connect_to(host, host_port); | |
1708 | if (sock > 0) { | |
1709 | /* Allocate a channel for this connection. */ | |
1710 | newch = channel_allocate(SSH_CHANNEL_OPEN, sock, originator_string); | |
1711 | channels[newch].remote_id = remote_channel; | |
1712 | ||
1713 | packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); | |
1714 | packet_put_int(remote_channel); | |
1715 | packet_put_int(newch); | |
1716 | packet_send(); | |
1717 | } else { | |
1718 | packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); | |
1719 | packet_put_int(remote_channel); | |
1720 | packet_send(); | |
1721 | } | |
1722 | xfree(host); | |
8efc0c15 | 1723 | } |
1724 | ||
aa3378df | 1725 | /* |
1726 | * Creates an internet domain socket for listening for X11 connections. | |
1727 | * Returns a suitable value for the DISPLAY variable, or NULL if an error | |
1728 | * occurs. | |
1729 | */ | |
8efc0c15 | 1730 | |
48e671d5 | 1731 | #define NUM_SOCKS 10 |
1732 | ||
5260325f | 1733 | char * |
95f1eccc | 1734 | x11_create_display_inet(int screen_number, int x11_display_offset) |
8efc0c15 | 1735 | { |
57112b5a | 1736 | int display_number, sock; |
1737 | u_short port; | |
48e671d5 | 1738 | struct addrinfo hints, *ai, *aitop; |
1739 | char strport[NI_MAXSERV]; | |
1740 | int gaierr, n, num_socks = 0, socks[NUM_SOCKS]; | |
1741 | char display[512]; | |
5260325f | 1742 | char hostname[MAXHOSTNAMELEN]; |
1743 | ||
95f1eccc | 1744 | for (display_number = x11_display_offset; |
5260325f | 1745 | display_number < MAX_DISPLAYS; |
1746 | display_number++) { | |
1747 | port = 6000 + display_number; | |
48e671d5 | 1748 | memset(&hints, 0, sizeof(hints)); |
1749 | hints.ai_family = IPv4or6; | |
1750 | hints.ai_flags = AI_PASSIVE; /* XXX loopback only ? */ | |
1751 | hints.ai_socktype = SOCK_STREAM; | |
1752 | snprintf(strport, sizeof strport, "%d", port); | |
1753 | if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) { | |
1754 | error("getaddrinfo: %.100s", gai_strerror(gaierr)); | |
5260325f | 1755 | return NULL; |
1756 | } | |
48e671d5 | 1757 | for (ai = aitop; ai; ai = ai->ai_next) { |
1758 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
1759 | continue; | |
1760 | sock = socket(ai->ai_family, SOCK_STREAM, 0); | |
1761 | if (sock < 0) { | |
80a44451 | 1762 | if (errno != EINVAL) { |
1763 | error("socket: %.100s", strerror(errno)); | |
1764 | return NULL; | |
1765 | } else { | |
22d89d24 | 1766 | debug("x11_create_display_inet: Socket family %d not supported", |
1767 | ai->ai_family); | |
80a44451 | 1768 | continue; |
1769 | } | |
48e671d5 | 1770 | } |
1771 | if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) { | |
1772 | debug("bind port %d: %.100s", port, strerror(errno)); | |
1773 | shutdown(sock, SHUT_RDWR); | |
1774 | close(sock); | |
16218745 | 1775 | |
1776 | if (ai->ai_next) | |
1777 | continue; | |
1778 | ||
48e671d5 | 1779 | for (n = 0; n < num_socks; n++) { |
1780 | shutdown(socks[n], SHUT_RDWR); | |
1781 | close(socks[n]); | |
1782 | } | |
1783 | num_socks = 0; | |
1784 | break; | |
1785 | } | |
1786 | socks[num_socks++] = sock; | |
80faa19f | 1787 | #ifndef DONT_TRY_OTHER_AF |
48e671d5 | 1788 | if (num_socks == NUM_SOCKS) |
1789 | break; | |
80faa19f | 1790 | #else |
1791 | break; | |
1792 | #endif | |
5260325f | 1793 | } |
48e671d5 | 1794 | if (num_socks > 0) |
1795 | break; | |
5260325f | 1796 | } |
1797 | if (display_number >= MAX_DISPLAYS) { | |
1798 | error("Failed to allocate internet-domain X11 display socket."); | |
1799 | return NULL; | |
8efc0c15 | 1800 | } |
5260325f | 1801 | /* Start listening for connections on the socket. */ |
48e671d5 | 1802 | for (n = 0; n < num_socks; n++) { |
1803 | sock = socks[n]; | |
1804 | if (listen(sock, 5) < 0) { | |
1805 | error("listen: %.100s", strerror(errno)); | |
1806 | shutdown(sock, SHUT_RDWR); | |
1807 | close(sock); | |
1808 | return NULL; | |
1809 | } | |
8efc0c15 | 1810 | } |
48e671d5 | 1811 | |
5260325f | 1812 | /* Set up a suitable value for the DISPLAY variable. */ |
a7effaac | 1813 | |
5260325f | 1814 | if (gethostname(hostname, sizeof(hostname)) < 0) |
1815 | fatal("gethostname: %.100s", strerror(errno)); | |
a7effaac | 1816 | |
1817 | #ifdef IPADDR_IN_DISPLAY | |
1818 | /* | |
1819 | * HPUX detects the local hostname in the DISPLAY variable and tries | |
1820 | * to set up a shared memory connection to the server, which it | |
1821 | * incorrectly supposes to be local. | |
1822 | * | |
1823 | * The workaround - as used in later $$H and other programs - is | |
1824 | * is to set display to the host's IP address. | |
1825 | */ | |
1826 | { | |
1827 | struct hostent *he; | |
1828 | struct in_addr my_addr; | |
1829 | ||
1830 | he = gethostbyname(hostname); | |
1831 | if (he == NULL) { | |
1832 | error("[X11-broken-fwd-hostname-workaround] Could not get " | |
1833 | "IP address for hostname %s.", hostname); | |
1834 | ||
1835 | packet_send_debug("[X11-broken-fwd-hostname-workaround]" | |
1836 | "Could not get IP address for hostname %s.", hostname); | |
1837 | ||
1838 | shutdown(sock, SHUT_RDWR); | |
1839 | close(sock); | |
1840 | ||
1841 | return NULL; | |
1842 | } | |
1843 | ||
1844 | memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr)); | |
1845 | ||
1846 | /* Set DISPLAY to <ip address>:screen.display */ | |
48e671d5 | 1847 | snprintf(display, sizeof(display), "%.50s:%d.%d", inet_ntoa(my_addr), |
a7effaac | 1848 | display_number, screen_number); |
1849 | } | |
1850 | #else /* IPADDR_IN_DISPLAY */ | |
1851 | /* Just set DISPLAY to hostname:screen.display */ | |
48e671d5 | 1852 | snprintf(display, sizeof display, "%.400s:%d.%d", hostname, |
a7effaac | 1853 | display_number, screen_number); |
1854 | #endif /* IPADDR_IN_DISPLAY */ | |
5260325f | 1855 | |
48e671d5 | 1856 | /* Allocate a channel for each socket. */ |
1857 | for (n = 0; n < num_socks; n++) { | |
1858 | sock = socks[n]; | |
0b242b12 | 1859 | (void) channel_new("x11 listener", |
1860 | SSH_CHANNEL_X11_LISTENER, sock, sock, -1, | |
1861 | CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, | |
1862 | 0, xstrdup("X11 inet listener")); | |
48e671d5 | 1863 | } |
5260325f | 1864 | |
1865 | /* Return a suitable value for the DISPLAY environment variable. */ | |
48e671d5 | 1866 | return xstrdup(display); |
8efc0c15 | 1867 | } |
1868 | ||
1869 | #ifndef X_UNIX_PATH | |
1870 | #define X_UNIX_PATH "/tmp/.X11-unix/X" | |
1871 | #endif | |
1872 | ||
1873 | static | |
1874 | int | |
2f450969 | 1875 | connect_local_xsocket(unsigned int dnr) |
8efc0c15 | 1876 | { |
5260325f | 1877 | static const char *const x_sockets[] = { |
1878 | X_UNIX_PATH "%u", | |
1879 | "/var/X/.X11-unix/X" "%u", | |
1880 | "/usr/spool/sockets/X11/" "%u", | |
1881 | NULL | |
1882 | }; | |
1883 | int sock; | |
1884 | struct sockaddr_un addr; | |
1885 | const char *const * path; | |
1886 | ||
1887 | for (path = x_sockets; *path; ++path) { | |
1888 | sock = socket(AF_UNIX, SOCK_STREAM, 0); | |
1889 | if (sock < 0) | |
1890 | error("socket: %.100s", strerror(errno)); | |
1891 | memset(&addr, 0, sizeof(addr)); | |
1892 | addr.sun_family = AF_UNIX; | |
1893 | snprintf(addr.sun_path, sizeof addr.sun_path, *path, dnr); | |
1894 | if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0) | |
1895 | return sock; | |
1896 | close(sock); | |
1897 | } | |
1898 | error("connect %.100s: %.100s", addr.sun_path, strerror(errno)); | |
1899 | return -1; | |
8efc0c15 | 1900 | } |
1901 | ||
0b242b12 | 1902 | int |
1903 | x11_connect_display(void) | |
8efc0c15 | 1904 | { |
0b242b12 | 1905 | int display_number, sock = 0; |
5260325f | 1906 | const char *display; |
0b242b12 | 1907 | char buf[1024], *cp; |
48e671d5 | 1908 | struct addrinfo hints, *ai, *aitop; |
1909 | char strport[NI_MAXSERV]; | |
1910 | int gaierr; | |
5260325f | 1911 | |
5260325f | 1912 | /* Try to open a socket for the local X server. */ |
1913 | display = getenv("DISPLAY"); | |
1914 | if (!display) { | |
1915 | error("DISPLAY not set."); | |
0b242b12 | 1916 | return -1; |
5260325f | 1917 | } |
aa3378df | 1918 | /* |
1919 | * Now we decode the value of the DISPLAY variable and make a | |
1920 | * connection to the real X server. | |
1921 | */ | |
1922 | ||
1923 | /* | |
1924 | * Check if it is a unix domain socket. Unix domain displays are in | |
1925 | * one of the following formats: unix:d[.s], :d[.s], ::d[.s] | |
1926 | */ | |
5260325f | 1927 | if (strncmp(display, "unix:", 5) == 0 || |
1928 | display[0] == ':') { | |
1929 | /* Connect to the unix domain socket. */ | |
1930 | if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) { | |
1931 | error("Could not parse display number from DISPLAY: %.100s", | |
1932 | display); | |
0b242b12 | 1933 | return -1; |
5260325f | 1934 | } |
1935 | /* Create a socket. */ | |
1936 | sock = connect_local_xsocket(display_number); | |
1937 | if (sock < 0) | |
0b242b12 | 1938 | return -1; |
5260325f | 1939 | |
1940 | /* OK, we now have a connection to the display. */ | |
0b242b12 | 1941 | return sock; |
5260325f | 1942 | } |
aa3378df | 1943 | /* |
1944 | * Connect to an inet socket. The DISPLAY value is supposedly | |
1945 | * hostname:d[.s], where hostname may also be numeric IP address. | |
1946 | */ | |
5260325f | 1947 | strncpy(buf, display, sizeof(buf)); |
1948 | buf[sizeof(buf) - 1] = 0; | |
1949 | cp = strchr(buf, ':'); | |
1950 | if (!cp) { | |
1951 | error("Could not find ':' in DISPLAY: %.100s", display); | |
0b242b12 | 1952 | return -1; |
5260325f | 1953 | } |
1954 | *cp = 0; | |
aa3378df | 1955 | /* buf now contains the host name. But first we parse the display number. */ |
5260325f | 1956 | if (sscanf(cp + 1, "%d", &display_number) != 1) { |
1957 | error("Could not parse display number from DISPLAY: %.100s", | |
1958 | display); | |
0b242b12 | 1959 | return -1; |
5260325f | 1960 | } |
5260325f | 1961 | |
48e671d5 | 1962 | /* Look up the host address */ |
1963 | memset(&hints, 0, sizeof(hints)); | |
1964 | hints.ai_family = IPv4or6; | |
1965 | hints.ai_socktype = SOCK_STREAM; | |
1966 | snprintf(strport, sizeof strport, "%d", 6000 + display_number); | |
1967 | if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) { | |
1968 | error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr)); | |
0b242b12 | 1969 | return -1; |
8efc0c15 | 1970 | } |
48e671d5 | 1971 | for (ai = aitop; ai; ai = ai->ai_next) { |
1972 | /* Create a socket. */ | |
1973 | sock = socket(ai->ai_family, SOCK_STREAM, 0); | |
1974 | if (sock < 0) { | |
1975 | debug("socket: %.100s", strerror(errno)); | |
7368a6c8 | 1976 | continue; |
1977 | } | |
1978 | /* Connect it to the display. */ | |
1979 | if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) { | |
1980 | debug("connect %.100s port %d: %.100s", buf, | |
1981 | 6000 + display_number, strerror(errno)); | |
1982 | close(sock); | |
1983 | continue; | |
1984 | } | |
1985 | /* Success */ | |
1986 | break; | |
48e671d5 | 1987 | } |
48e671d5 | 1988 | freeaddrinfo(aitop); |
1989 | if (!ai) { | |
6ae2364d | 1990 | error("connect %.100s port %d: %.100s", buf, 6000 + display_number, |
48e671d5 | 1991 | strerror(errno)); |
0b242b12 | 1992 | return -1; |
8efc0c15 | 1993 | } |
0b242b12 | 1994 | return sock; |
1995 | } | |
5260325f | 1996 | |
0b242b12 | 1997 | /* |
1998 | * This is called when SSH_SMSG_X11_OPEN is received. The packet contains | |
1999 | * the remote channel number. We should do whatever we want, and respond | |
2000 | * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE. | |
2001 | */ | |
5260325f | 2002 | |
0b242b12 | 2003 | void |
188adeb2 | 2004 | x11_input_open(int type, int plen, void *ctxt) |
0b242b12 | 2005 | { |
2006 | int remote_channel, sock = 0, newch; | |
2007 | char *remote_host; | |
2008 | unsigned int remote_len; | |
5260325f | 2009 | |
0b242b12 | 2010 | /* Get remote channel number. */ |
2011 | remote_channel = packet_get_int(); | |
5260325f | 2012 | |
0b242b12 | 2013 | /* Get remote originator name. */ |
2014 | if (have_hostname_in_open) { | |
2015 | remote_host = packet_get_string(&remote_len); | |
2016 | remote_len += 4; | |
2017 | } else { | |
2018 | remote_host = xstrdup("unknown (remote did not supply name)"); | |
2019 | remote_len = 0; | |
2020 | } | |
2021 | ||
2022 | debug("Received X11 open request."); | |
2023 | packet_integrity_check(plen, 4 + remote_len, SSH_SMSG_X11_OPEN); | |
2024 | ||
2025 | /* Obtain a connection to the real X display. */ | |
2026 | sock = x11_connect_display(); | |
2027 | if (sock == -1) { | |
2028 | /* Send refusal to the remote host. */ | |
2029 | packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); | |
2030 | packet_put_int(remote_channel); | |
2031 | packet_send(); | |
2032 | } else { | |
2033 | /* Allocate a channel for this connection. */ | |
2034 | newch = channel_allocate( | |
2035 | (x11_saved_proto == NULL) ? | |
2036 | SSH_CHANNEL_OPEN : SSH_CHANNEL_X11_OPEN, | |
2037 | sock, remote_host); | |
2038 | channels[newch].remote_id = remote_channel; | |
2039 | ||
2040 | /* Send a confirmation to the remote host. */ | |
2041 | packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); | |
2042 | packet_put_int(remote_channel); | |
2043 | packet_put_int(newch); | |
2044 | packet_send(); | |
2045 | } | |
8efc0c15 | 2046 | } |
2047 | ||
aa3378df | 2048 | /* |
2049 | * Requests forwarding of X11 connections, generates fake authentication | |
2050 | * data, and enables authentication spoofing. | |
2051 | */ | |
8efc0c15 | 2052 | |
6ae2364d | 2053 | void |
0b242b12 | 2054 | x11_request_forwarding_with_spoofing(int client_session_id, |
2055 | const char *proto, const char *data) | |
8efc0c15 | 2056 | { |
5260325f | 2057 | unsigned int data_len = (unsigned int) strlen(data) / 2; |
2058 | unsigned int i, value; | |
2059 | char *new_data; | |
2060 | int screen_number; | |
2061 | const char *cp; | |
2062 | u_int32_t rand = 0; | |
2063 | ||
2064 | cp = getenv("DISPLAY"); | |
2065 | if (cp) | |
2066 | cp = strchr(cp, ':'); | |
2067 | if (cp) | |
2068 | cp = strchr(cp, '.'); | |
2069 | if (cp) | |
2070 | screen_number = atoi(cp + 1); | |
2071 | else | |
2072 | screen_number = 0; | |
2073 | ||
2074 | /* Save protocol name. */ | |
2075 | x11_saved_proto = xstrdup(proto); | |
2076 | ||
aa3378df | 2077 | /* |
2078 | * Extract real authentication data and generate fake data of the | |
2079 | * same length. | |
2080 | */ | |
5260325f | 2081 | x11_saved_data = xmalloc(data_len); |
2082 | x11_fake_data = xmalloc(data_len); | |
2083 | for (i = 0; i < data_len; i++) { | |
2084 | if (sscanf(data + 2 * i, "%2x", &value) != 1) | |
2085 | fatal("x11_request_forwarding: bad authentication data: %.100s", data); | |
2086 | if (i % 4 == 0) | |
2087 | rand = arc4random(); | |
2088 | x11_saved_data[i] = value; | |
2089 | x11_fake_data[i] = rand & 0xff; | |
2090 | rand >>= 8; | |
2091 | } | |
2092 | x11_saved_data_len = data_len; | |
2093 | x11_fake_data_len = data_len; | |
2094 | ||
2095 | /* Convert the fake data into hex. */ | |
2096 | new_data = xmalloc(2 * data_len + 1); | |
2097 | for (i = 0; i < data_len; i++) | |
2098 | sprintf(new_data + 2 * i, "%02x", (unsigned char) x11_fake_data[i]); | |
2099 | ||
2100 | /* Send the request packet. */ | |
0b242b12 | 2101 | if (compat20) { |
2102 | channel_request_start(client_session_id, "x11-req", 0); | |
2103 | packet_put_char(0); /* XXX bool single connection */ | |
2104 | } else { | |
2105 | packet_start(SSH_CMSG_X11_REQUEST_FORWARDING); | |
2106 | } | |
2107 | packet_put_cstring(proto); | |
2108 | packet_put_cstring(new_data); | |
5260325f | 2109 | packet_put_int(screen_number); |
2110 | packet_send(); | |
2111 | packet_write_wait(); | |
2112 | xfree(new_data); | |
8efc0c15 | 2113 | } |
2114 | ||
2115 | /* Sends a message to the server to request authentication fd forwarding. */ | |
2116 | ||
6ae2364d | 2117 | void |
5260325f | 2118 | auth_request_forwarding() |
8efc0c15 | 2119 | { |
5260325f | 2120 | packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING); |
2121 | packet_send(); | |
2122 | packet_write_wait(); | |
8efc0c15 | 2123 | } |
2124 | ||
aa3378df | 2125 | /* |
2126 | * Returns the name of the forwarded authentication socket. Returns NULL if | |
2127 | * there is no forwarded authentication socket. The returned value points to | |
2128 | * a static buffer. | |
2129 | */ | |
8efc0c15 | 2130 | |
5260325f | 2131 | char * |
2132 | auth_get_socket_name() | |
8efc0c15 | 2133 | { |
5260325f | 2134 | return channel_forwarded_auth_socket_name; |
8efc0c15 | 2135 | } |
2136 | ||
2137 | /* removes the agent forwarding socket */ | |
2138 | ||
6ae2364d | 2139 | void |
5260325f | 2140 | cleanup_socket(void) |
2141 | { | |
77bb0bca | 2142 | unlink(channel_forwarded_auth_socket_name); |
5260325f | 2143 | rmdir(channel_forwarded_auth_socket_dir); |
8efc0c15 | 2144 | } |
2145 | ||
aa3378df | 2146 | /* |
fa649821 | 2147 | * This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server. |
aa3378df | 2148 | * This starts forwarding authentication requests. |
2149 | */ | |
8efc0c15 | 2150 | |
fa649821 | 2151 | int |
5260325f | 2152 | auth_input_request_forwarding(struct passwd * pw) |
8efc0c15 | 2153 | { |
5260325f | 2154 | int sock, newch; |
2155 | struct sockaddr_un sunaddr; | |
2156 | ||
2157 | if (auth_get_socket_name() != NULL) | |
2158 | fatal("Protocol error: authentication forwarding requested twice."); | |
2159 | ||
2160 | /* Temporarily drop privileged uid for mkdir/bind. */ | |
2161 | temporarily_use_uid(pw->pw_uid); | |
2162 | ||
2163 | /* Allocate a buffer for the socket name, and format the name. */ | |
2164 | channel_forwarded_auth_socket_name = xmalloc(MAX_SOCKET_NAME); | |
2165 | channel_forwarded_auth_socket_dir = xmalloc(MAX_SOCKET_NAME); | |
2166 | strlcpy(channel_forwarded_auth_socket_dir, "/tmp/ssh-XXXXXXXX", MAX_SOCKET_NAME); | |
2167 | ||
2168 | /* Create private directory for socket */ | |
fa649821 | 2169 | if (mkdtemp(channel_forwarded_auth_socket_dir) == NULL) { |
2170 | packet_send_debug("Agent forwarding disabled: mkdtemp() failed: %.100s", | |
2171 | strerror(errno)); | |
2172 | restore_uid(); | |
2173 | xfree(channel_forwarded_auth_socket_name); | |
2174 | xfree(channel_forwarded_auth_socket_dir); | |
2175 | channel_forwarded_auth_socket_name = NULL; | |
2176 | channel_forwarded_auth_socket_dir = NULL; | |
2177 | return 0; | |
2178 | } | |
5260325f | 2179 | snprintf(channel_forwarded_auth_socket_name, MAX_SOCKET_NAME, "%s/agent.%d", |
2180 | channel_forwarded_auth_socket_dir, (int) getpid()); | |
2181 | ||
2182 | if (atexit(cleanup_socket) < 0) { | |
2183 | int saved = errno; | |
2184 | cleanup_socket(); | |
2185 | packet_disconnect("socket: %.100s", strerror(saved)); | |
2186 | } | |
2187 | /* Create the socket. */ | |
2188 | sock = socket(AF_UNIX, SOCK_STREAM, 0); | |
2189 | if (sock < 0) | |
2190 | packet_disconnect("socket: %.100s", strerror(errno)); | |
2191 | ||
2192 | /* Bind it to the name. */ | |
2193 | memset(&sunaddr, 0, sizeof(sunaddr)); | |
2194 | sunaddr.sun_family = AF_UNIX; | |
2195 | strncpy(sunaddr.sun_path, channel_forwarded_auth_socket_name, | |
2196 | sizeof(sunaddr.sun_path)); | |
2197 | ||
2198 | if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0) | |
2199 | packet_disconnect("bind: %.100s", strerror(errno)); | |
2200 | ||
2201 | /* Restore the privileged uid. */ | |
2202 | restore_uid(); | |
2203 | ||
2204 | /* Start listening on the socket. */ | |
2205 | if (listen(sock, 5) < 0) | |
2206 | packet_disconnect("listen: %.100s", strerror(errno)); | |
2207 | ||
2208 | /* Allocate a channel for the authentication agent socket. */ | |
2209 | newch = channel_allocate(SSH_CHANNEL_AUTH_SOCKET, sock, | |
2210 | xstrdup("auth socket")); | |
a408af76 | 2211 | strlcpy(channels[newch].path, channel_forwarded_auth_socket_name, |
2212 | sizeof(channels[newch].path)); | |
fa649821 | 2213 | return 1; |
8efc0c15 | 2214 | } |
2215 | ||
2216 | /* This is called to process an SSH_SMSG_AGENT_OPEN message. */ | |
2217 | ||
6ae2364d | 2218 | void |
188adeb2 | 2219 | auth_input_open_request(int type, int plen, void *ctxt) |
8efc0c15 | 2220 | { |
5260325f | 2221 | int remch, sock, newch; |
2222 | char *dummyname; | |
2223 | ||
7368a6c8 | 2224 | packet_integrity_check(plen, 4, type); |
2225 | ||
5260325f | 2226 | /* Read the remote channel number from the message. */ |
2227 | remch = packet_get_int(); | |
2228 | ||
aa3378df | 2229 | /* |
2230 | * Get a connection to the local authentication agent (this may again | |
2231 | * get forwarded). | |
2232 | */ | |
5260325f | 2233 | sock = ssh_get_authentication_socket(); |
2234 | ||
aa3378df | 2235 | /* |
2236 | * If we could not connect the agent, send an error message back to | |
2237 | * the server. This should never happen unless the agent dies, | |
2238 | * because authentication forwarding is only enabled if we have an | |
2239 | * agent. | |
2240 | */ | |
5260325f | 2241 | if (sock < 0) { |
2242 | packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); | |
2243 | packet_put_int(remch); | |
2244 | packet_send(); | |
2245 | return; | |
2246 | } | |
2247 | debug("Forwarding authentication connection."); | |
2248 | ||
aa3378df | 2249 | /* |
2250 | * Dummy host name. This will be freed when the channel is freed; it | |
2251 | * will still be valid in the packet_put_string below since the | |
2252 | * channel cannot yet be freed at that point. | |
2253 | */ | |
5260325f | 2254 | dummyname = xstrdup("authentication agent connection"); |
2255 | ||
2256 | newch = channel_allocate(SSH_CHANNEL_OPEN, sock, dummyname); | |
2257 | channels[newch].remote_id = remch; | |
2258 | ||
2259 | /* Send a confirmation to the remote host. */ | |
2260 | packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); | |
2261 | packet_put_int(remch); | |
2262 | packet_put_int(newch); | |
2263 | packet_send(); | |
8efc0c15 | 2264 | } |
7e7327a1 | 2265 | |
2266 | void | |
0b242b12 | 2267 | channel_start_open(int id) |
7e7327a1 | 2268 | { |
2269 | Channel *c = channel_lookup(id); | |
2270 | if (c == NULL) { | |
2271 | log("channel_open: %d: bad id", id); | |
2272 | return; | |
2273 | } | |
0b242b12 | 2274 | debug("send channel open %d", id); |
7e7327a1 | 2275 | packet_start(SSH2_MSG_CHANNEL_OPEN); |
2276 | packet_put_cstring(c->ctype); | |
2277 | packet_put_int(c->self); | |
2278 | packet_put_int(c->local_window); | |
2279 | packet_put_int(c->local_maxpacket); | |
0b242b12 | 2280 | } |
2281 | void | |
2282 | channel_open(int id) | |
2283 | { | |
2284 | /* XXX REMOVE ME */ | |
2285 | channel_start_open(id); | |
7e7327a1 | 2286 | packet_send(); |
7e7327a1 | 2287 | } |
2288 | void | |
2289 | channel_request(int id, char *service, int wantconfirm) | |
2290 | { | |
2291 | channel_request_start(id, service, wantconfirm); | |
2292 | packet_send(); | |
2293 | debug("channel request %d: %s", id, service) ; | |
2294 | } | |
2295 | void | |
2296 | channel_request_start(int id, char *service, int wantconfirm) | |
2297 | { | |
2298 | Channel *c = channel_lookup(id); | |
2299 | if (c == NULL) { | |
2300 | log("channel_request: %d: bad id", id); | |
2301 | return; | |
2302 | } | |
2303 | packet_start(SSH2_MSG_CHANNEL_REQUEST); | |
2304 | packet_put_int(c->remote_id); | |
2305 | packet_put_cstring(service); | |
2306 | packet_put_char(wantconfirm); | |
2307 | } | |
2308 | void | |
2309 | channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg) | |
2310 | { | |
2311 | Channel *c = channel_lookup(id); | |
2312 | if (c == NULL) { | |
2313 | log("channel_register_callback: %d: bad id", id); | |
2314 | return; | |
2315 | } | |
2316 | c->cb_event = mtype; | |
2317 | c->cb_fn = fn; | |
2318 | c->cb_arg = arg; | |
2319 | } | |
2320 | void | |
2321 | channel_register_cleanup(int id, channel_callback_fn *fn) | |
2322 | { | |
2323 | Channel *c = channel_lookup(id); | |
2324 | if (c == NULL) { | |
2325 | log("channel_register_cleanup: %d: bad id", id); | |
2326 | return; | |
2327 | } | |
2328 | c->dettach_user = fn; | |
2329 | } | |
2330 | void | |
2331 | channel_cancel_cleanup(int id) | |
2332 | { | |
2333 | Channel *c = channel_lookup(id); | |
2334 | if (c == NULL) { | |
2335 | log("channel_cancel_cleanup: %d: bad id", id); | |
2336 | return; | |
2337 | } | |
2338 | c->dettach_user = NULL; | |
2339 | } | |
2e73a022 | 2340 | void |
2341 | channel_register_filter(int id, channel_filter_fn *fn) | |
2342 | { | |
2343 | Channel *c = channel_lookup(id); | |
2344 | if (c == NULL) { | |
2345 | log("channel_register_filter: %d: bad id", id); | |
2346 | return; | |
2347 | } | |
2348 | c->input_filter = fn; | |
2349 | } | |
7e7327a1 | 2350 | |
2351 | void | |
2352 | channel_set_fds(int id, int rfd, int wfd, int efd, int extusage) | |
2353 | { | |
2354 | Channel *c = channel_lookup(id); | |
2355 | if (c == NULL || c->type != SSH_CHANNEL_LARVAL) | |
2356 | fatal("channel_activate for non-larval channel %d.", id); | |
0fbe8c74 | 2357 | |
2358 | channel_register_fds(c, rfd, wfd, efd, extusage); | |
7e7327a1 | 2359 | c->type = SSH_CHANNEL_OPEN; |
7e7327a1 | 2360 | /* XXX window size? */ |
bcbf86ec | 2361 | c->local_window = c->local_window_max = c->local_maxpacket * 2; |
7e7327a1 | 2362 | packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
2363 | packet_put_int(c->remote_id); | |
2364 | packet_put_int(c->local_window); | |
2365 | packet_send(); | |
2366 | } |